Flu

What is the flu?

The flu, also called Influenza, is a contagious respiratory illness caused by influenza viruses. It affects the nose, throat, and lungs. Each year, millions of people in the United States get the flu. While many recover without complications, it can be serious — especially for adults over 65, young children, pregnant women, and people with chronic medical conditions.

What causes the flu?

The flu is caused by influenza viruses that spread from person to person through:

• Coughing, sneezing, or talking (respiratory droplets)
• Touching contaminated surfaces and then touching your mouth, nose, or eyes

You are most contagious in the first 3–4 days after your illness begins.

What are the symptoms of the flu?

Flu symptoms usually come on suddenly and may include:

• Fever or chills
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headache
• Fatigue
• Vomiting and diarrhea (more common in children)

Cold vs. Flu

Note: “Stomach flu” is not influenza — it is Gastroenteritis, a digestive illness.

What complications can the flu cause?

Some people develop serious complications, including:

• Bronchitis
• Ear or sinus infections
• Pneumonia
• Inflammation of the heart (myocarditis)
• Brain inflammation (encephalitis)
• Muscle inflammation (myositis)

The flu can also worsen chronic conditions like asthma, diabetes, or heart disease.

How is the flu diagnosed?

A health care provider may:

• Review your symptoms and medical history
• Use a nasal or throat swab test

Some rapid tests give results in 15–20 minutes, but may be less accurate than more advanced laboratory tests.

What are the treatments for the flu?

Most people recover with:

• Rest
• Fluids
• Staying home to prevent spreading illness

High-risk individuals or those with severe symptoms may need antiviral medicines, which work best if started within 48 hours of symptom onset.

Can the flu be prevented?

The best prevention is an annual flu vaccine.

Other protective measures include:

• Washing hands often
• Covering coughs and sneezes
• Avoiding close contact with sick individuals

Source: Centers for Disease Control and Prevention (CDC)

H1N1 is a strain of influenza that caused a global outbreak in 2009. It is commonly referred to as H1N1 influenza.

Symptoms

Similar to seasonal flu:

• Fever
• Cough
• Sore throat
• Body aches
• Fatigue

Prevention

• Annual flu vaccination
• Hand hygiene
• Staying home when sick
• Avoiding close contact with infected individuals

Antiviral medicines can treat or help prevent illness after exposure.

Source: Centers for Disease Control and Prevention (CDC)

What is bird flu?

Avian influenza is caused by influenza viruses that primarily infect birds. In rare cases, certain strains can infect humans.

Strains that have caused human illness include:

• H5N1
• H7N9
• H5N6

Human infections have mainly occurred in Asia, Africa, Europe, and parts of the Middle East.

How do people get bird flu?

Most cases happen after:

• Direct contact with infected birds
• Touching contaminated surfaces
• Breathing contaminated droplets or dust

Rarely, infection may occur from infected animals or other humans. Eating properly cooked poultry and eggs is safe.

Symptoms

• Fever
• Cough
• Sore throat
• Muscle aches
• Conjunctivitis
• Difficulty breathing

Severe cases may cause pneumonia.

Treatment & Prevention

• Early antiviral treatment
• Protective equipment for workers exposed to birds
• Safe food handling
• Avoiding raw milk

There is currently no public vaccine available for bird flu.

Source: Centers for Disease Control and Prevention (CDC)

What is the flu shot?

The flu shot is a vaccine that protects against influenza viruses expected to circulate each year. Getting vaccinated is the most effective way to reduce your risk of illness and serious complications.

Benefits of the flu shot

• Reduces your chance of getting the flu
• Makes illness milder if you do get sick
• Lowers risk of hospitalization
• Protects high-risk individuals
• Protects infants when given during pregnancy

Who should get it?

The CDC recommends annual vaccination for everyone 6 months and older, with rare exceptions.

It is especially important for:

• Adults 65+
• Pregnant women
• Young children
• People with chronic illnesses

Side effects

Usually mild and short-lived:

• Soreness at injection site
• Mild fever
• Headache
• Muscle aches

Serious allergic reactions are rare.

Source: Centers for Disease Control and Prevention (CDC)

What is gastroenteritis?

Gastroenteritis is inflammation of the stomach and intestines. It commonly causes vomiting and diarrhea. It is often mistakenly called “stomach flu,” but it is not caused by influenza viruses.

Causes

• Viruses (most common, such as norovirus and rotavirus)
• Bacteria
• Parasites
• Food poisoning
• Certain medications

Symptoms

• Diarrhea
• Abdominal pain
• Nausea and vomiting
• Fever

Severe cases may cause dehydration.

Warning signs (seek medical care if present)

Adults:

• Diarrhea lasting more than 2 days
• High fever
• Bloody or black stools
• Severe abdominal pain
• Signs of dehydration

Children:

• No wet diapers for 3+ hours
• No tears when crying
• Persistent vomiting
• High fever

Treatment

Most people recover with:

• Rest
• Fluids and electrolytes
• Possibly probiotics

Antibiotics or antiparasitic medicines may be used for certain infections.

Prevention

• Wash hands thoroughly
• Disinfect contaminated surfaces
• Practice safe food handling
• Vaccinate infants against rotavirus

What are zoonotic diseases?

Animal diseases that people can catch are called zoonoses. Many infectious diseases affecting humans originate in animals or animal products. These diseases can spread directly from animals or indirectly through contaminated environments, food, or water.

How can zoonotic diseases spread?

You can get a zoonotic disease through:

• Direct contact with an infected animal
• Touching contaminated surfaces (such as fencing, buckets, cages, or bedding)
• Handling animal waste
• Bites or scratches
• Insect vectors such as ticks or mosquitoes

Farm Animals

Farm animals can carry harmful germs. After touching animals—or objects they have touched—wash your hands thoroughly. Adults should supervise children visiting farms or petting zoos and ensure proper handwashing.

Wild Animals

Wild animals may carry bacteria, viruses, and parasites even if they appear healthy.

Examples include:

• Deer and deer mice that carry ticks linked to Lyme disease
• Wildlife that may carry rabies

It is safest to enjoy wildlife from a distance.

Pets

The risk of illness from household pets is low, but it is possible.

Examples include:

• Reptiles (turtles, snakes, iguanas) that may carry Salmonella
• Dogs that can transmit rabies if unvaccinated
• Cats that can spread toxoplasmosis through litter

How to Reduce Risk

• Wash hands after handling animals
• Keep pet areas clean
• Avoid handling wild animals
• Keep pets’ vaccinations up to date
• Practice safe food handling

Source: Centers for Disease Control and Prevention (CDC)

What are antibiotics?

Antibiotics are medicines used to treat bacterial infections in people and animals. They work by killing bacteria or stopping them from growing and multiplying.

They may be taken:

• By mouth (pills, capsules, liquids)
• On the skin (creams, sprays, ointments)
• As eye or ear drops
• By injection or intravenously (IV) for serious infections

What do antibiotics treat?

Antibiotics treat certain bacterial infections, such as:

• Strep throat
• Urinary tract infections (UTIs)
• Some types of pneumonia
• E. coli infections

Not all bacterial infections require antibiotics. Your health care provider determines when they are necessary.

Do antibiotics treat viruses?

No. Antibiotics do not work against viral infections, including:

• Colds
• Most sore throats
• Flu
• Most cases of bronchitis

Taking antibiotics when they are not needed can cause harm.

Possible Side Effects

Common side effects:

• Rash
• Nausea
• Diarrhea
• Yeast infections

Serious side effects:

• Clostridioides difficile (C. diff) infection
• Severe allergic reactions
• Antibiotic-resistant infections

Contact your provider if you experience side effects.

Antibiotic Resistance

Antibiotic resistance happens when bacteria change and become resistant to antibiotics. This makes infections harder to treat.

To help prevent resistance:

• Only take antibiotics when prescribed
• Finish the full course, even if you feel better
• Do not share antibiotics
• Do not save leftover antibiotics

Source: Centers for Disease Control and Prevention (CDC)

What is chronic bronchitis?

Chronic bronchitis is a type of chronic obstructive pulmonary disease (COPD). It involves long-term inflammation of the bronchial tubes, which carry air to and from the lungs.

The inflammation causes:

• Swelling of airways
• Excess mucus production
• Difficulty moving air in and out of the lungs

Causes

The primary cause is long-term exposure to lung irritants, especially:

• Cigarette smoking (most common cause)
• Secondhand smoke
• Air pollution
• Workplace dust and chemical fumes

Rarely, a genetic condition called alpha-1 antitrypsin deficiency may contribute

Risk Factors

• Smoking history
• Age over 40
• Long-term exposure to irritants
• Family history of COPD

Symptoms

Symptoms usually worsen over time and may include:

• Persistent cough with mucus
• Wheezing
• Shortness of breath
• Chest tightness
• Frequent respiratory infections

Severe cases may cause swelling in the legs, muscle weakness, and weight loss.

Diagnosis

Diagnosis may include:

• Medical history
• Physical examination
• Lung function tests (spirometry)
• Chest X-ray or CT scan
• Blood tests

Treatment

There is no cure, but treatment can improve quality of life:

Lifestyle Changes

• Quit smoking
• Avoid lung irritants
• Maintain healthy nutrition
• Stay physically active as recommended

Medications

• Bronchodilators (inhalers)
• Steroids (for inflammation)
• Vaccines (flu and pneumococcal)
• Antibiotics for infections

Other Treatments

• Oxygen therapy (for severe cases)
• Pulmonary rehabilitation
• Lung transplant (rare, severe cases)

Prevention

The most effective prevention is avoiding smoking and lung irritants.

Source: National Heart, Lung, and Blood Institute (NHLBI)

What is COVID-19?

COVID-19 is a respiratory illness caused by a coronavirus called SARS-CoV-2. The virus spreads when an infected person breathes out droplets or tiny airborne particles that contain the virus. These particles can be inhaled by others nearby.

COVID-19 ranges from mild illness to severe disease and can be especially serious for:

• Older adults
• People with chronic medical conditions
• Individuals with weakened immune systems

Symptoms

Symptoms may appear 2–14 days after exposure and can include:

• Fever or chills
• Cough
• Shortness of breath
• Fatigue
• Muscle or body aches
• Loss of taste or smell
• Sore throat
• Congestion or runny nose
• Nausea, vomiting, or diarrhea

Severe symptoms require emergency medical attention, including trouble breathing or chest pain.

Prevention

You can reduce your risk by:

• Staying up to date with COVID-19 vaccines
• Washing hands frequently
• Improving indoor ventilation
• Wearing a mask in high-risk settings when appropriate
• Staying home when sick

Additional resources include information on:

• COVID-19 testing
• COVID-19 vaccines
• Post-COVID conditions (long COVID)

Source: Centers for Disease Control and Prevention (CDC)

What is diarrhea?

Diarrhea is the passage of loose, watery stools three or more times in one day.

• Acute diarrhea lasts a short time (usually 1–2 days).
• Chronic diarrhea lasts four weeks or longer and may signal an underlying condition.

Causes

Common causes include:

• Bacterial infections (from contaminated food or water)
• Viral infections such as norovirus or rotavirus
• Parasites
• Certain medicines (e.g., antibiotics, cancer treatments)
• Food intolerances (e.g., lactose intolerance)
• Digestive diseases such as Crohn’s disease
• Irritable bowel syndrome (IBS)

Sometimes, no specific cause is found.

Symptoms

You may also experience:

• Abdominal cramps
• Urgent need to use the bathroom
• Fever
• Bloody stools (in some infections)

Risk of Dehydration

Diarrhea can cause dehydration, which may be serious for:

• Infants and young children
• Older adults
• People with weakened immune systems

When to Seek Medical Care

Contact a health care provider if you have:

• Signs of dehydration
• Diarrhea lasting more than 2 days (adults) or 24 hours (children)
• Severe abdominal pain
• Fever of 102°F (39°C) or higher
• Blood or pus in stools
• Black, tarry stools

Treatment

Treatment focuses on replacing fluids and electrolytes.

Adults should drink:

• Water
• Broths
• Oral rehydration drinks
• Caffeine-free beverages

Children should use oral rehydration solutions designed for pediatric use.

Medicines may be needed in certain cases.

Prevention

You can reduce risk by:

• Washing hands thoroughly
• Practicing safe food handling
• Using safe drinking water
• Receiving the rotavirus vaccine (for infants)
• Taking precautions while traveling

Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

What is emphysema?

Emphysema is a type of chronic obstructive pulmonary disease (COPD) that damages the air sacs (alveoli) in the lungs.

Normally, air sacs are elastic and expand and deflate with each breath. In emphysema:

• The walls between air sacs are destroyed
• Air sacs become larger and less elastic
• Oxygen exchange becomes less efficient

This makes breathing increasingly difficult.

Causes

The main cause is long-term exposure to lung irritants, especially:

• Cigarette smoking
• Secondhand smoke
• Air pollution
• Workplace dust and chemical fumes

A rare genetic condition called alpha-1 antitrypsin deficiency can also cause emphysema.

Symptoms

Symptoms worsen over time and may include:

• Shortness of breath
• Chronic cough
• Wheezing
• Chest tightness
• Frequent respiratory infections

Severe disease may lead to weight loss and muscle weakness.

Treatment

There is no cure, but treatments help manage symptoms.

Lifestyle Changes

• Quit smoking
• Avoid lung irritants
• Maintain proper nutrition
• Engage in appropriate physical activity

Medications

• Bronchodilators (inhalers)
• Steroids (in some cases)
• Vaccines (flu and pneumococcal)
• Antibiotics for infections

Advanced Treatments

• Oxygen therapy
• Pulmonary rehabilitation
• Surgery (lung volume reduction or transplant in severe cases)

Prevention

Avoiding smoking is the most effective prevention strategy.

Source: National Heart, Lung, and Blood Institute (NHLBI)

What is heart disease?

Heart disease refers to various conditions that affect the heart. It is a form of cardiovascular disease and remains the leading cause of death in the United States.

Types of Heart Disease

Coronary Artery Disease (CAD)

The most common type. It occurs when plaque builds up in the arteries supplying blood to the heart.

CAD can lead to:

• Angina (chest pain)
• Heart attack
• Heart failure
• Arrhythmia

Other Types

• Heart valve diseases
• Cardiomyopathy (heart muscle disease)
• Congenital heart defects

Risk Factors

Some risk factors cannot be changed:

• Age
• Family history
• Genetics
• Race/ethnicity

Others can be managed:

• Smoking
• High blood pressure
• High cholesterol
• Diabetes
• Obesity
• Physical inactivity
• Excess alcohol use

Treatment

Treatment depends on the type and severity and may include:

• Heart-healthy lifestyle changes
• Medicines
• Procedures or surgery
• Cardiac rehabilitation

Prevention

You can reduce risk by:

• Eating a balanced diet
• Staying physically active
• Not smoking
• Managing chronic conditions

Source: National Heart, Lung, and Blood Institute (NHLBI)

HIV weakens the immune system by destroying infection-fighting white blood cells. This increases the risk of opportunistic infections (OIs) — infections that are more severe in people with weakened immunity.

Types of Opportunistic Infections

Bacterial

• Tuberculosis
• Mycobacterium avium complex (MAC)

Viral

• Cytomegalovirus (CMV)
• Hepatitis C

Fungal

• Yeast infections
• Cryptococcal meningitis
• Pneumocystis pneumonia (PCP)

Parasitic

• Cryptosporidiosis
• Toxoplasmosis

Prevention

You can reduce infection risk by:

• Taking HIV medicines consistently
• Practicing safe sex
• Washing hands frequently
• Cooking food thoroughly
• Staying up to date with vaccinations

Source: National Institutes of Health (NIH)

What is rotavirus?

Rotavirus is a highly contagious virus that causes gastroenteritis (inflammation of the stomach and intestines). It is a leading cause of severe diarrhea in infants and young children. Almost all children in the United States are infected with rotavirus at least once before their fifth birthday.

Symptoms

Symptoms usually begin about two days after exposure and may include:

• Severe watery diarrhea
• Vomiting
• Fever
• Abdominal pain
• Dehydration

Symptoms typically last 3 to 8 days.

Complications

The most serious risk is dehydration, especially in infants and young children. Signs of dehydration include:

• Dry mouth
• Crying without tears
• Urinating less than usual
• Lethargy

Severe cases may require hospitalization for IV fluids.

Treatment

There is no specific medicine to cure rotavirus. Treatment focuses on:

• Drinking plenty of fluids
• Using oral rehydration solutions
• Monitoring for signs of dehydration

Prevention

Two vaccines are available to protect against rotavirus. They are given to babies in two or three doses, depending on the brand.

Vaccination significantly reduces severe illness and hospitalization.

Source: Centers for Disease Control and Prevention (CDC)

What are staph infections?

Staphylococcus (staph) is a group of bacteria. The species Staphylococcus aureus causes most infections.

Staph bacteria commonly live on the skin or in the nose without causing illness. Infection occurs when bacteria enter the body through a cut or wound.

Types of Staph Infections

Staph bacteria can cause:

• Skin infections (most common)
• Bacteremia (bloodstream infection)
• Sepsis
• Bone infections
• Endocarditis (infection of heart lining/valves)
• Food poisoning
• Pneumonia
• Toxic shock syndrome (TSS)

Risk Factors

You may be at higher risk if you:

• Have diabetes, cancer, eczema, or lung disease
• Have a weakened immune system
• Are hospitalized
• Use medical devices (catheters, pacemakers, artificial joints)
• Inject drugs
• Play contact sports
• Have burns

Symptoms

Symptoms vary by infection type:

Skin infections:

• Red, swollen, painful bumps
• Pus or drainage
• Warm skin

Severe infections may include:

• Fever and chills
• Shortness of breath
• Rapid heartbeat
• Confusion

Treatment

Treatment usually includes antibiotics:

• Topical creams
• Oral antibiotics
• IV antibiotics for severe infections

Some strains, such as MRSA (methicillin-resistant Staphylococcus aureus), are resistant to many antibiotics but can still be treated with specific medications.

Infected wounds may need drainage. Severe cases may require surgery.

Prevention

To reduce risk:

• Wash hands frequently
• Keep wounds clean and covered
• Avoid sharing personal items
• Practice safe food handling
• Clean shared athletic equipment

Source: Centers for Disease Control and Prevention (CDC)

What are vaccines?

Vaccines train your immune system to recognize and fight harmful germs. They are given as:

• Shots
• Pills
• Liquids
• Nasal sprays

Vaccines protect against diseases caused by viruses and bacteria.

Types of Vaccines

There are several types:

• Live-attenuated vaccines (weakened germ)
• Inactivated vaccines (killed germ)
• Subunit, recombinant, polysaccharide, and conjugate vaccines (specific pieces of the germ)
• Toxoid vaccines (bacterial toxin)
• mRNA vaccines
• Viral vector vaccines

All types stimulate an immune response that provides protection.

Why Vaccines Matter

Vaccines:

• Prevent serious illness
• Reduce complications
• Protect vulnerable populations
• Lower disease outbreaks

Immunity from vaccination is safer than immunity gained from infection.

Community Immunity (Herd Immunity)

When enough people are vaccinated, diseases spread less easily. This protects:

• Newborns
• People with weakened immune systems
• Individuals who cannot receive certain vaccines

Are Vaccines Safe?

Yes. Vaccines undergo extensive testing and monitoring before approval in the United States.

Vaccine Schedule

The CDC publishes recommended vaccine schedules for children and adults. Following the schedule ensures protection at the right time.

Source: Centers for Disease Control and Prevention (CDC)

What is acute bronchitis?

Acute bronchitis is inflammation of the bronchial tubes — the airways that carry air to your lungs.

It usually develops after a cold or respiratory infection.

Symptoms

• Persistent cough (often with mucus)
• Wheezing
• Chest tightness
• Mild fever
• Shortness of breath

The cough may last several weeks, even after the infection improves.

Causes

Most cases are caused by viruses — the same ones that cause colds and flu. Less commonly, bacteria may cause acute bronchitis.

Risk factors include:

• Tobacco smoke exposure
• Air pollution
• Dust and chemical fumes

Treatment

Treatment focuses on symptom relief:

• Rest
• Fluids
• Fever reducers (acetaminophen; aspirin for adults only)
• Humidified air
• Inhalers may help if wheezing is present

Antibiotics are not helpful unless the infection is bacterial.

Source: National Heart, Lung, and Blood Institute (NHLBI)

What is an allergy?

An allergy is an overreaction of the immune system to a substance that is usually harmless to most people.

These substances are called allergens.

Common Allergens

• Pollen
• Dust mites
• Mold
• Pet dander
• Foods
• Insect stings
• Medicines

Symptoms

Allergy symptoms may include:

• Sneezing
• Runny or stuffy nose
• Itchy eyes or skin
• Rashes
• Swelling
• Asthma symptoms

Severe Reaction: Anaphylaxis

Anaphylaxis is a life-threatening allergic reaction that requires emergency treatment. Symptoms may include:

• Difficulty breathing
• Swelling of the throat
• Rapid pulse
• Dizziness

Diagnosis

Doctors may use:

• Skin tests
• Blood tests

Treatment

Treatment options include:

• Antihistamines
• Nasal sprays
• Inhalers
• Allergy shots (immunotherapy)
• Avoiding triggers

Genes and environmental factors both play a role in allergies.

Source: National Institute of Allergy and Infectious Diseases (NIAID), NIH

What is Alpha-1 Antitrypsin Deficiency?

Alpha-1 antitrypsin deficiency (AAT deficiency or AATD) is an inherited condition that increases the risk of lung disease and liver disease.

Alpha-1 antitrypsin (AAT) is a protein made in the liver. It protects the lungs from inflammation and damage caused by irritants such as:

• Cigarette smoke
• Air pollution
• Dust and environmental toxins

If your body does not produce enough AAT, your lungs can become damaged over time. This may lead to chronic obstructive pulmonary disease (COPD). AAT deficiency can also cause liver disease, including cirrhosis, especially in children.

What Causes AAT Deficiency?

AAT deficiency is a genetic disorder caused by changes (mutations) in the SERPINA1 gene, which provides instructions for making the AAT protein. You inherit one copy of this gene from each parent.

• Two abnormal copies → You have AAT deficiency and a higher risk of lung or liver disease, often before age 45.
• One abnormal copy → You are a carrier. Carriers have a slightly increased risk of lung disease and can pass the gene to their children.

Some gene changes:

• Reduce the amount of AAT produced
• Prevent any AAT from being made
• Cause AAT to build up in the liver, leading to liver damage

Symptoms

Some people never develop symptoms. When symptoms appear, they often develop between ages 20 and 50.

Lung symptoms:

• Wheezing
• Shortness of breath
• Chronic cough with mucus
• Frequent respiratory infections
• Chest pain
• Fatigue
• Unexplained weight loss

Liver symptoms:

• Jaundice (yellowing of skin or eyes)
• Swelling in the legs or abdomen
• Abnormal liver tests

Rarely, skin problems such as painful lumps may occur

Diagnosis

Your provider may test you if you have:

• Early COPD
• Unexplained liver disease
• Family history of AAT deficiency

Testing may include:

• Blood test to measure AAT levels
• Genetic testing (genotype or phenotype testing)
• Lung function tests

Genetic testing confirms the diagnosis.

Treatment

There is no cure, but treatments can slow lung damage and manage symptoms.

Treatment options include:

• Inhaled medications
• Pulmonary rehabilitation
• Oxygen therapy
• Augmentation therapy (lifelong IV treatment using donor AAT protein)
• Lung surgery or transplant (severe cases)
• Liver transplant (if severe liver damage occurs)

Lifestyle changes are critical:

• Quit smoking
• Avoid secondhand smoke and pollution
• Limit or avoid alcohol

Source: National Heart, Lung, and Blood Institute (NHLBI)

What is Antibiotic Resistance?

Antibiotics treat bacterial infections. However, bacteria can change over time and become resistant to antibiotics. When this happens:

• Antibiotics no longer work
• Infections become harder to treat
• Treatment may require stronger, more expensive medications

Antibiotic resistance affects the bacteria — not your body.

Resistant Infections

Examples include:

• MRSA (methicillin-resistant Staphylococcus aureus)
• Drug-resistant tuberculosis (TB)

Resistant infections may require:

• Longer hospital stays
• Stronger medications
• Intensive follow-up care

How Resistance Happens

Bacteria naturally evolve. When antibiotics are overused or misused, resistant bacteria survive and multiply.

Antibiotics do not work for viral infections such as:

• Colds
• Flu
• Most sore throats
• Many sinus infections

Who Is at Higher Risk?

• People with weakened immune systems
• Hospitalized patients
• People taking antibiotics long-term
• Premature infants
• Older adults

Prevention

You can help reduce resistance by:

• Taking antibiotics only when prescribed
• Completing the full course
• Never sharing antibiotics
• Not saving antibiotics for later
• Practicing good hygiene

Source: Centers for Disease Control and Prevention (CDC)

What Is Asthma?

Asthma is a chronic lung disease that causes inflammation and narrowing of the airways. It can lead to:

• Wheezing
• Coughing
• Chest tightness
• Breathing difficulty

When symptoms suddenly worsen, it is called an asthma attack.

Causes and Triggers

The exact cause is unknown. Genetics and environment both play roles.

Common triggers:

• Allergic triggers:
  • Dust mites
  • Mold
  • Pet dander
  • Pollen
  • Cockroaches
• Nonallergic triggers:
  • Cold air
  • Respiratory infections
  • Tobacco smoke
  • Air pollution
  • Exercise

Triggers can vary from child to child.

Risk Factors

Children are more likely to develop asthma if they:

• Are exposed to secondhand smoke
• Have a family history of asthma
• Have allergies or obesity
• Have frequent viral infections
• Are Black or Puerto Rican

Symptoms in Children

• Nighttime coughing
• Wheezing
• Shortness of breath
• Rapid breathing
• Fatigue
• Irritability

Severe attack warning signs:

• Blue lips or fingernails
• Severe breathing difficulty
• Inability to speak

Seek emergency care immediately if these occur.

Treatment

Treatment plans usually include:

1. Avoiding triggers
2. Quick-relief medications (rescue inhalers)
3. Long-term control medicines

Regular follow-up is important to adjust treatment.

Source: National Heart, Lung, and Blood Institute (NHLBI)

Bell’s palsy is the most common cause of sudden facial paralysis. It usually affects one side of the face.

Symptoms

• Facial weakness or paralysis
• Drooping eyelid or mouth
• Twitching
• Drooling
• Dry eye or mouth
• Changes in taste

Symptoms peak within 48 hours.

Causes

Scientists believe a viral infection causes swelling of the facial nerve.

Higher risk groups include:

• Pregnant women
• People with diabetes
• People with recent viral infections

Recovery

• 75% of patients recover without treatment
• Most begin improving within two weeks
• Full recovery often occurs within 3–6 months

Source: National Institute of Neurological Disorders and Stroke (NINDS)

What is Botox?

Botox is a medication made from a purified toxin produced by Clostridium botulinum. In small doses, it is used safely to treat medical and cosmetic conditions.

Medical Uses

Botox may be used for:

• Wrinkle reduction
• Severe underarm sweating
• Chronic migraine
• Cervical dystonia
• Blepharospasm (uncontrollable blinking)
• Strabismus (crossed eyes)
• Overactive bladder

How It Works

Botox blocks nerve signals to certain muscles, temporarily weakening or relaxing them. Effects typically last 3 to 12 months.

Side Effects

Common side effects:

• Injection site pain
• Swelling or bruising
• Headache
• Flu-like symptoms

Facial injections may cause temporary eyelid drooping.

Botox should not be used during pregnancy or breastfeeding.

What Is Cancer?

Cancer is not just one disease — it is a group of more than 100 diseases. Cancer begins in your body’s cells, the basic building blocks of life.

Normally, your body:

• Creates new cells when needed
• Removes old or damaged cells

Cancer develops when this process breaks down:

• New cells grow even when they aren’t needed
• Old cells do not die when they should

These extra cells can form a tumor.

Types of Tumors

• Benign tumors – Not cancer; they do not spread.
• Malignant tumors – Cancerous; they can invade nearby tissue and spread.

When cancer spreads from one part of the body to another, it is called metastasis.

Symptoms and treatment depend on:

• The type of cancer
• The stage (how advanced it is)

Types of Cancer

Cancer can begin almost anywhere in the body. It is usually named for where it starts, such as:

• Lung cancer
• Breast cancer
• Colon cancer

Cancer may also be classified by cell type:

• Carcinoma – Starts in epithelial cells (most common type)
• Sarcoma – Begins in bone, muscle, fat, or connective tissue
• Leukemia – Affects blood-forming tissues
• Lymphoma – Affects the immune system

How Cancer Develops

Cancer is a genetic disease caused by changes (mutations) in DNA. Some mutations are inherited or develop over time due to environmental exposures.

Risk factors include:

• Smoking
• Excessive sun exposure (UV radiation)
• Poor diet
• Physical inactivity
• Aging

Symptoms of Cancer

Symptoms vary depending on the type. Warning signs may include:

• A new lump or mass
• Unexplained bleeding or bruising
• Blood in urine or stool
• A sore that won’t heal
• Difficulty swallowing
• A new or changing mole
• Unexplained weight loss

Cancer may not cause pain early on. Persistent symptoms lasting more than a few weeks should be evaluated.

Diagnosis

There is no single test for cancer. Diagnosis may involve:

• Medical and family history
• Physical exam
• Screening tests (mammogram, colonoscopy, Pap test)
• Blood tests
• Imaging (CT scan, MRI, X-ray)
• Biopsy (removing tissue to examine under a microscope)

Treatment

Treatment depends on the type and stage. Common treatments include:

• Surgery
• Radiation therapy
• Chemotherapy
• Hormone therapy
• Immunotherapy
• Targeted therapy
• Stem cell transplant

Many treatment plans use a combination of therapies.

Prevention

While not all cancers are preventable, you can reduce risk by:

• Avoiding tobacco
• Limiting sun exposure
• Maintaining a healthy weight
• Staying physically active
• Limiting alcohol
• Eating a balanced diet

Source: National Cancer Institute (NCI)

What Is Immunotherapy?

Immunotherapy is a type of cancer treatment that helps your immune system recognize and attack cancer cells.

It is a form of biological therapy, meaning it uses substances made from living organisms or laboratory versions of them.

How It Works

Cancer cells can hide from the immune system. Immunotherapy helps by:

• Marking cancer cells so the immune system can find them
• Boosting immune activity
• Blocking cancer cells’ ability to suppress immune responses

Some immunotherapies are a form of targeted therapy, focusing on specific cancer cell features.

How It Is Given

Immunotherapy may be given:

• Intravenously (IV)
• As pills or capsules
• As a cream (for certain skin cancers)
• Directly into the bladder (for bladder cancer)

Treatment schedules vary depending on the cancer type and response.

Side Effects

Common side effects include:

• Skin reactions at the IV site
• Flu-like symptoms
• Fatigue

Rarely, severe immune reactions may occur. Close monitoring is essential.

Source: National Cancer Institute (NCI)

Learning to Live With Cancer

A cancer diagnosis can affect nearly every aspect of life, including:

• Work and daily routines
• Relationships
• Self-image

Many people adjust over time, but it can be one of life’s greatest challenges.

Coping With Emotions

Common feelings include:

• Fear
• Sadness
• Anger
• Guilt
• Anxiety

Helpful coping strategies:

• Talking with someone you trust
• Journaling
• Relaxation techniques (meditation, breathing exercises)
• Staying engaged in enjoyable activities

If feelings become overwhelming, speak with your provider. Support for depression and anxiety is available.

Communicating With Your Health Care Team

Strong communication improves care. Consider:

• Writing down questions before appointments
• Bringing a trusted person with you
• Telling providers how much detail you want

Your care team may include doctors, nurses, social workers, dietitians, and pharmacists.

Adjusting to Changes

Cancer and its treatment may cause:

• Fatigue
• Hair loss
• Scarring
• Changes in sexual health

Strategies that may help:

• Gentle exercise (with provider approval)
• Counseling
• Staying socially connected

Follow-up care after treatment is essential to monitor recovery and detect recurrence.

Source: National Cancer Institute (NCI)

Children’s health includes:

• Physical well-being
• Mental health
• Social development

Key foundations include:

• Nutritious foods
• Adequate sleep
• Regular exercise
• Safety practices
• Routine checkups

When to See a Provider

Seek medical care for:

• Significant weight changes
• Behavioral or sleep changes
• Fever over 102°F
• Persistent sore throat
• Breathing problems
• Skin rashes or infections

Regular well-child visits help monitor growth and development.

What Is CKD?

Chronic kidney disease (CKD) occurs when your kidneys are damaged and cannot properly filter blood.

Kidneys normally:

• Remove waste and excess fluid
• Balance electrolytes
• Control blood pressure
• Produce hormones

CKD develops slowly over time.

Causes

The most common causes are:

• Diabetes
• High blood pressure

Symptoms

Early CKD often has no symptoms. As it progresses, symptoms may include:

• Fatigue
• Swelling
• Changes in urination
• High blood pressure

Blood and urine tests are needed for diagnosis.

Treatment

There is no cure, but treatment can slow progression:

• Blood pressure control
• Blood sugar management
• Cholesterol-lowering medications

If kidney failure occurs, treatment options include:

• Dialysis
• Kidney transplant

Protecting Your Kidneys

You can help protect kidney health by:

• Reducing salt intake
• Managing blood pressure
• Controlling diabetes
• Limiting alcohol
• Maintaining a healthy weight
• Exercising regularly
• Avoiding smoking

Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Staying Healthy in College

College is an exciting time filled with new opportunities, independence, and personal growth. It can also bring stress, pressure, and important health decisions. Balancing academics, social life, and self-care is essential for staying healthy.

You can protect your physical and mental health by:

• Eating a balanced diet with fruits, vegetables, lean protein, and whole grains
• Getting enough sleep (7–9 hours per night)
• Exercising regularly
• Keeping up with vaccinations and checkups
• Practicing safe sex if sexually active
• Making informed choices about alcohol and drugs
• Seeking help if you feel overwhelmed, anxious, or depressed

College health centers offer confidential services, counseling, and preventive care. Reaching out early makes a difference.

Source: Centers for Disease Control and Prevention (CDC)

Common Infant Illnesses

It can be stressful when your baby is sick. Fortunately, many common infant illnesses are mild and manageable at home.

Common conditions in babies include:

• Colds and coughs
• Fever
• Vomiting
• Diaper rash
• Cradle cap

Most of these issues are not serious. However, knowing the warning signs is important.

When to Call a Health Care Provider

Contact your provider immediately if your baby has:

• A high or persistent fever
• Trouble breathing
• Signs of dehydration (fewer wet diapers, dry mouth)
• Extreme sleepiness or irritability
• Vomiting that will not stop

Trust your instincts. If something feels wrong, it is always appropriate to call.

Overview

COVID-19 is caused by the SARS-CoV-2 virus. Vaccination helps prevent severe illness, hospitalization, and death.

In the United States, COVID-19 vaccines have been authorized by the U.S. Food and Drug Administration (FDA) under Emergency Use Authorization (EUA) and approved after meeting strict safety and effectiveness standards.

Why Vaccination Matters

COVID-19 vaccines:

• Reduce the risk of severe disease
• Lower hospitalization rates
• Decrease the risk of complications
• Help protect vulnerable populations

Vaccination programs continue to evolve based on scientific evidence and circulating variants.

Source: Centers for Disease Control and Prevention (CDC)

Cystic fibrosis is an inherited disease that affects the mucus and sweat glands.

It primarily impacts the:

• Lungs
• Pancreas
• Liver
• Intestines
• Sinuses
• Reproductive organs

What Happens in CF?

CF causes mucus to become thick and sticky. This:

• Clogs airways
• Traps bacteria
• Leads to repeated lung infections
• Causes long-term lung damage

Severity varies widely. Some people have symptoms at birth, while others develop them later in childhood or adulthood.

Diagnosis

Testing may include:

• Genetic testing
• Blood tests
• Sweat chloride test

Treatment

Although there is no cure, treatments have significantly improved survival and quality of life. Treatment options include:

• Chest physical therapy
• Airway clearance techniques
• Respiratory medications
• Nutritional support
• Exercise
• Targeted CFTR-modulator therapies

Many individuals with CF now live into their 40s, 50s, and beyond.

Source: NIH – National Heart, Lung, and Blood Institute (NHLBI)

What Is Delirium?

Delirium is a sudden change in mental status. It causes confusion, disorientation, and difficulty thinking clearly. It usually develops over hours or days and is often temporary.

Types of Delirium

• Hypoactive– Sleepy, withdrawn, low activity
• Hyperactive– Agitated, restless
• Mixed– Alternates between hypoactive and hyperactive

Causes

Delirium can result from many conditions, including:

• Infections (UTI, pneumonia, flu)
• Dehydration or electrolyte imbalance
• Alcohol or drug intoxication or withdrawal
• Medication side effects
• Surgery or anesthesia reactions
• Severe illness
• Organ failure
• Dementia
• Sleep deprivation

Higher risk is associated with:

• Older age
• Hospitalization (especially ICU)
• Dementia
• Multiple chronic illnesses
• Surgery
• High doses of opioids or sedatives

Symptoms

Symptoms may fluctuate throughout the day and include:

• Sudden confusion
• Difficulty focusing
• Disorganized speech
• Memory problems
• Changes in alertness
• Hallucinations or delusions
• Sleep disturbances
• Emotional changes (anger, anxiety, irritability)

Delirium vs. Dementia

• Delirium: Sudden onset, fluctuates, may include hallucinations
• Dementia: Gradual onset, progressive, usually begins with memory loss

A person can have both at the same time.

Diagnosis

Evaluation may include:

• Medical history
• Physical and neurological exams
• Mental status testing
• Lab tests
• Imaging studies

Treatment

Treatment focuses on identifying and correcting the underlying cause. Supportive measures may include:

• Maintaining a quiet, well-lit room
• Providing clocks and calendars
• Ensuring use of hearing aids or glasses
• Managing pain
• Minimizing sedative medications

Recovery may take days to months depending on severity.

Prevention

• Avoiding unnecessary sedatives
• Maintaining hydration
• Promoting regular sleep
• Encouraging mobility
• Family involvement during hospital stays

What Is Diabetes?

Diabetes (diabetes mellitus) is a chronic condition in which blood glucose (blood sugar) levels are too high.

Glucose is your body’s main source of energy. It comes from the food you eat and is also produced by your body. Insulin, a hormone made by the pancreas, helps move glucose from your bloodstream into your cells to be used for energy.

If you have diabetes:

• Your body does not make enough insulin
• Your body does not use insulin properly
• Or both

As a result, glucose builds up in the blood instead of entering the cells. Over time, high blood sugar can lead to serious health complications — but with proper management, many complications can be prevented or delayed.

Types of Diabetes

Type 1 Diabetes

• An autoimmune condition
• The immune system destroys insulin-producing cells
• The body makes little or no insulin
• Often begins in childhood, but can develop at any age

Type 2 Diabetes

• The most common type
• The body makes insulin but does not use it effectively (insulin resistance)
• Develops gradually, often over years

Gestational Diabetes

• Develops during pregnancy
• Usually resolves after delivery
• Increases future risk of type 2 diabetes

Risk Factors

Type 1

• Family history (parent or sibling with type 1 diabetes)

Type 2

• Overweight or obesity
• Age over 35 (though younger people can develop it)
• Family history
• Prediabetes
• Physical inactivity
• High blood pressure
• Polycystic ovary syndrome (PCOS)
• History of gestational diabetes
• Certain racial and ethnic backgrounds (including African American, Hispanic/Latino, American Indian, Asian American, and Pacific Islander populations)

Gestational Diabetes

• Overweight or obesity
• Family history
• Previous gestational diabetes
• PCOS

Symptoms

Common symptoms include:

• Increased thirst
• Frequent urination (especially at night)
• Increased hunger
• Fatigue
• Blurred vision
• Slow-healing sores
• Numbness or tingling in hands or feet
• Unexplained weight loss

Type 1 symptoms appear quickly and can be severe.

Type 2 symptoms develop gradually and may go unnoticed.

Gestational diabetes often has no symptoms and is detected through routine screening.

Diagnosis

Diagnosis is made with blood glucose testing, including:

• A1C test
• Fasting blood glucose
• Oral glucose tolerance test

Treatment

Treatment focuses on managing blood glucose levels:

Type 1

• Daily insulin (injections or insulin pump)
• Sometimes additional medications

Type 2

• Healthy diet
• Regular physical activity
• Weight management
• Oral or injectable medications (if needed)

Gestational Diabetes

• Healthy eating
• Exercise
• Monitoring blood glucose
• Sometimes insulin

Regular blood glucose monitoring is essential for all types.

Prevention

• Type 1 diabetes cannot be prevented.
• Type 2 diabetes may be delayed or prevented through:
  • Healthy eating
  • Regular exercise
  • Maintaining a healthy weight

Source: NIH – National Institute of Diabetes and Digestive and Kidney Diseases

What Is Encephalitis?

Encephalitis is inflammation (swelling) of the brain. It can range from mild illness to a life-threatening condition.

Causes

Infectious Encephalitis

Most commonly caused by viruses, including:

• Herpes viruses (HSV, Epstein-Barr, varicella-zoster)
• Tick-borne viruses
• Mosquito-borne viruses (such as West Nile virus)
• Enteroviruses

Rarely, bacteria, fungi, or parasites may cause it.

Autoimmune Encephalitis

Occurs when the immune system mistakenly attacks healthy brain tissue. It may be triggered by infections, tumors, or sometimes an unknown cause.

Risk Factors

You are at higher risk if you:

• Have a weakened immune system
• Are very young or older
• Live in areas with mosquito or tick exposure

Symptoms

Mild cases may cause:

• Fever
• Headache
• Fatigue
• Body aches

Severe cases may cause:

• Stiff neck
• Seizures
• Behavior changes
• Drowsiness
• Muscle weakness or paralysis
• Confusion
• Coma

In infants:

• Poor feeding
• Vomiting
• Irritability
• Bulging soft spot on the head

Immediate medical care is essential for severe symptoms.

Diagnosis

Evaluation may include:

• Physical and neurologic exams
• Brain imaging (CT or MRI)
• EEG
• Blood tests
• Cerebrospinal fluid (CSF) testing

Treatment

Hospital care is usually required. Treatment depends on the cause and may include:

• Antiviral medicines
• Antibiotics
• Corticosteroids
• Supportive care (fluids, nutrition)
• Rehabilitation therapies may be needed during recovery

Prevention

• Practice good hand hygiene
• Get recommended vaccinations
• Prevent mosquito and tick bites

Source: NIH – National Institute of Neurological Disorders and Stroke

What Is Fatty Liver Disease?

Fatty liver disease occurs when excess fat builds up in the liver. The liver helps digest food, store energy, and remove toxins.

There are two main types:

• Nonalcoholic fatty liver disease (NAFLD)
• Alcoholic fatty liver disease

Nonalcoholic Fatty Liver Disease (NAFLD)

Not caused by heavy alcohol use. Types:

• Simple fatty liver – Fat buildup without inflammation
• Nonalcoholic steatohepatitis (NASH) – Fat, inflammation, and liver cell damage

NASH can lead to scarring (fibrosis), cirrhosis, or liver cancer.

Alcoholic Fatty Liver Disease

Caused by heavy alcohol use. Continued drinking may progress to alcoholic hepatitis and cirrhosis.

Risk Factors (NAFLD)

• Type 2 diabetes
• Obesity
• High cholesterol or triglycerides
• High blood pressure
• Metabolic syndrome
• Certain medications
• Rapid weight loss
• Hepatitis C

Symptoms

Often no symptoms. Possible symptoms:

• Fatigue
• Discomfort in the upper right abdomen

Diagnosis

• Medical history
• Physical exam
• Blood tests
• Imaging tests
• Sometimes liver biopsy

Treatment

For NAFLD:

• Weight loss
• Healthy diet
• Regular exercise

For alcohol-related disease:

• Complete alcohol cessation
• Advanced disease may require medical procedures or transplant

Helpful Lifestyle Changes

• Limit salt and sugar
• Eat fruits, vegetables, whole grains
• Exercise regularly
• Get recommended vaccines
• Avoid harmful supplements
• Limit alcohol

What Are Germs?

Germs are microscopic organisms found everywhere. They include:

• Bacteria
• Viruses
• Fungi
• Parasites

Some germs are harmless or helpful. Others cause infectious diseases.

How Germs Spread

• Close contact
• Coughing or sneezing
• Contaminated surfaces
• Food and water
• Insect or animal bites
• Mother to baby

How to Protect Yourself

• Wash hands for at least 20 seconds
• Cover coughs and sneezes
• Stay home when sick
• Avoid close contact with sick individuals
• Clean frequently touched surfaces
• Practice food safety

Hand hygiene is one of the most effective prevention tools.

Overview

Giant cell arteritis is an inflammatory condition affecting large and medium arteries, often in the scalp and neck. It most commonly affects people over age 50. It is frequently associated with polymyalgia rheumatica.

Symptoms

• Headache
• Scalp tenderness
• Jaw pain while chewing
• Vision problems (double vision or vision loss)
• Dizziness
• Fever
• Fatigue

Risks

If untreated, it can lead to:

• Permanent vision loss
• Stroke

Diagnosis

There is no single definitive test. Diagnosis may include:

• Medical history
• Physical exam
• Blood tests measuring inflammation

Treatment

Treatment typically includes corticosteroids. Early treatment is critical to prevent complications.

With proper treatment, recurrence is uncommon.

Source: NIH – National Institute of Arthritis and Musculoskeletal and Skin Diseases

What Is HIV?

HIV (human immunodeficiency virus) attacks the immune system by destroying a type of white blood cell that helps the body fight infection. Over time, this weakens the immune system and increases the risk of infections and certain diseases.

What Is AIDS?

AIDS (acquired immunodeficiency syndrome) is the most advanced stage of HIV infection. It occurs when the immune system is severely damaged and can no longer effectively fight off infections.

Not everyone with HIV develops AIDS—especially with early and consistent treatment.

How Does HIV Spread?

HIV spreads through certain body fluids from a person who has HIV. Transmission can occur:

• Through unprotected vaginal or anal sex
• By sharing needles or syringes
• Through contact with infected blood
• From mother to baby during pregnancy, childbirth, or breastfeeding

“Unprotected” means not using condoms or medicines that prevent or treat HIV.

Who Is at Higher Risk?

Anyone can get HIV. However, higher risk groups include:

• People with other sexually transmitted infections (STIs)
• People who inject drugs and share needles
• Gay and bisexual men
• Black/African American and Hispanic/Latino communities (disproportionately affected)
• Individuals who engage in high-risk sexual behaviors

Social factors such as stigma, discrimination, limited access to healthcare, income, and education also influence risk.

Symptoms

Early (Acute) HIV Infection: Symptoms may resemble the flu and appear within 2–4 weeks:

• Fever
• Chills
• Rash
• Night sweats
• Muscle aches
• Sore throat
• Fatigue
• Swollen lymph nodes
• Mouth ulcers

Symptoms may come and go.

Chronic HIV

Often no symptoms for years without treatment.

AIDS

Severely weakened immune system leading to opportunistic infections and serious illness. The only way to know for sure is to get tested.

Testing

HIV is diagnosed through a blood or oral fluid test. Testing options include:

• Health care provider testing
• Home testing kits
• Free testing sites (CDC Testing Locator)

Treatment

There is no cure for HIV, but it can be managed with antiretroviral therapy (ART).

ART:

• Reduces the amount of virus in the body
• Protects the immune system
• Prevents progression to AIDS
• Dramatically reduces transmission risk

With consistent treatment, many people with HIV live long, healthy lives.

Prevention

You can reduce risk by:

• Getting tested regularly
• Using condoms consistently
• Limiting number of sexual partners
• Avoiding shared needles
• Getting tested and treated for STIs

Preventive Medicines:

• PrEP (pre-exposure prophylaxis): Daily medication for people at high risk
• PEP (post-exposure prophylaxis): Emergency medication started within 72 hours after possible exposure

Source: NIH – National Institutes of Health

What Is the Immune System?

The immune system is a complex network of cells, tissues, and organs that work together to protect your body from infection and disease.

When germs invade, the immune system responds to fight them.

Parts of the Immune System

• Skin – Physical barrier against germs
• Mucous membranes – Trap and fight pathogens
• White blood cells – Attack infections
• Lymphatic system – Includes:
  • Thymus
  • Spleen
  • Tonsils
  • Lymph nodes
  • Bone marrow

How It Works

When the immune system detects a foreign substance (an antigen), it:

1. Launches an immune response
2. Produces antibodies
3. Creates memory cells

This memory helps protect against future infections — called immunity.

Types of Immunity

Innate Immunity

• You are born with it
• First line of defense

Active Immunity

• Develops after infection or vaccination
• Often long-lasting

Passive Immunity

• Antibodies received from another source
• Short-term protection
• Example: antibodies passed from mother to baby

Immune System Disorders

Problems can occur when the immune system:

• Overreacts (allergies, asthma)
• Attacks healthy tissue (autoimmune diseases)
• Does not function properly (immunodeficiency disorders)

HIV is an example of a disease that weakens the immune system.

Overview

Infections in health care settings can be serious. Infection control practices reduce the spread of disease.

Key Prevention Steps

• Proper handwashing
• Covering coughs and sneezes
• Staying current with vaccinations
• Using gloves, masks, and protective equipment
• Safe handling of blood and contaminated materials

Hand hygiene remains the most effective infection control measure.

Infectious Mononucleosis (Mono)

What Is Mono?

Infectious mononucleosis (mono) is usually caused by the Epstein-Barr virus (EBV). It is common among teenagers and young adults.

It spreads primarily through saliva, which is why it is sometimes called “the kissing disease”.

How It Spreads

• Kissing
• Sharing drinks, utensils, or lip products
• Contact with infected saliva
• Rarely through blood transfusion or organ transplant

Symptoms

Symptoms appear 4–6 weeks after infection:

• Extreme fatigue
• Fever
• Sore throat
• Swollen lymph nodes
• Head and body aches
• Rash
• Enlarged spleen or liver (less common)

Fatigue can last for weeks or months.

Diagnosis

Diagnosis is based on:

• Symptoms
• Physical exam
• Blood test (mono test)

Treatment

Since mono is caused by a virus:

• Rest
• Fluids
• Over-the-counter pain relievers (not aspirin in children)
• Antibiotics do not treat mono
• Avoid contact sports for about a month to prevent spleen rupture

Source: CDC – Centers for Disease Control and Prevention

Overview

A kidney transplant is surgery to place a healthy kidney into someone whose kidneys have failed. The transplanted kidney performs the function of both failed kidneys, eliminating the need for dialysis.

The Procedure

• The new kidney is placed in the lower abdomen
• Blood vessels are connected to allow blood flow
• The kidney may begin working immediately or within weeks
• The original kidneys are usually left in place unless there is a medical reason to remove them

Donor Sources

• Deceased donors
• Living donors (often family members)

Waiting times can be long

After Transplant

Patients must take immunosuppressant medicines for life to prevent rejection of the new kidney. Regular follow-up care is essential.

Source: NIH – National Institute of Diabetes and Digestive and Kidney Diseases

What Is Legionnaires’ Disease?

Legionnaires’ disease is a severe form of pneumonia caused by Legionella bacteria. The illness was first identified after an outbreak at an American Legion convention, which is how it got its name.

Legionella bacteria are naturally found in freshwater environments such as lakes and rivers. However, people typically become infected when the bacteria grow and spread in man-made water systems, including:

• Hot tubs
• Decorative fountains
• Cooling towers
• Large building plumbing systems (hotels, hospitals, nursing homes)

The bacteria can also cause Pontiac fever, a milder flu-like illness that does not affect the lungs.

How Does It Spread?

People become infected by breathing in tiny water droplets (mist) that contain the bacteria.

You generally cannot get Legionnaires’ disease by drinking contaminated water unless it enters your lungs (aspiration).

The disease does not usually spread from person to person.

Outbreaks occur when multiple people are exposed to the same contaminated water source.

Who Is at Higher Risk?

Most healthy individuals exposed to Legionella do not become ill. Higher-risk groups include:

• Adults over age 50
• Current or former smokers
• People with chronic diseases (diabetes, kidney failure)
• People with chronic lung disease (COPD, emphysema)
• Individuals with weakened immune systems (HIV, cancer, immunosuppressive medications)
• Residents of long-term care facilities
• People recently hospitalized or who had surgery requiring anesthesia

Symptoms

Symptoms usually appear 2–14 days after exposure and may include:

• Cough
• High fever
• Chills
• Chest pain
• Shortness of breath
• Fatigue
• Headache
• Nausea or vomiting
• Diarrhea
• Confusion

Complications

Legionnaires’ disease can cause serious complications, including:

• Respiratory failure
• Kidney failure
• Sepsis

Approximately 1 in 10 people who develop the disease die from complications.

Diagnosis

Diagnosis may include:

• Chest X-ray (to confirm pneumonia)
• Urine or sputum test (to detect Legionella)
• Blood tests

Treatment

Treatment requires antibiotics, often in a hospital setting. Early treatment significantly improves outcomes.

Prevention

Risk reduction strategies include:

• Regular cleaning of water-related devices (humidifiers, water heaters, air conditioners)
• Flushing faucets and showerheads if unused for a week or more
• Avoiding poorly maintained hot tubs or decorative fountains
• Proper building water system maintenance

Source: Centers for Disease Control and Prevention (CDC)

Malaria is a serious disease caused by parasites transmitted through the bite of an infected mosquito.

It remains a major cause of death worldwide, particularly in tropical and subtropical regions. In the United States, most cases occur in travelers returning from affected countries.

The most severe form is most common in sub-Saharan Africa.

Symptoms

• High fever
• Chills
• Flu-like illness
• Vomiting
• Diarrhea
• Jaundice

Malaria can be life-threatening but is treatable with medication.

Prevention for Travelers

If traveling to malaria-endemic areas:

• Take prescribed preventive medication
• Use insect repellent with DEET
• Wear protective clothing
• Sleep under mosquito nets

Source: Centers for Disease Control and Prevention (CDC)

Children are not simply small adults. Medication dosing and safety require special attention. Giving the wrong dose or an inappropriate medicine can cause serious harm.

Important Safety Tips

• Always read and follow label directions carefully
• Confirm that the medicine is appropriate for your child’s age and weight
• Use proper measuring devices (never kitchen spoons)
• Know measurement abbreviations (tsp., tbsp., mg, mL, oz.)
• Do not combine medicines without consulting a provider
• Store medications safely and out of reach

When to Contact a Health Care Provider

Contact a health care provider if:

• New symptoms appear
• Side effects occur
• The medicine does not seem effective

Source: U.S. Food and Drug Administration (FDA)

Overview

Mosquitoes are found worldwide. While most bites are harmless, some can transmit serious diseases.

Health Effects of Mosquito Bites

• Itchy bumps (most common reaction)
• Allergic reactions (rarely severe, including anaphylaxis)
• Transmission of diseases

Diseases Spread by Mosquitoes

• Chikungunya
• Dengue
• Malaria
• West Nile Virus
• Zika Virus

Some of these diseases can be severe or life-threatening.

Prevention

• Use EPA-registered insect repellent (DEET, picaridin, IR3535, oil of lemon eucalyptus)
• Wear long sleeves and pants
• Treat clothing with permethrin (not directly on skin)
• Install window and door screens
• Eliminate standing water
• Consult a health care provider before traveling to high-risk areas

Mpox (formerly called monkeypox) is caused by the monkeypox virus, related to the smallpox virus. It is mainly spread through close contact with someone who is infected.

Types of Mpox Viruses

• Clade I – More severe; found in Central and Eastern Africa
• Clade II – Less severe; responsible for the 2022 global outbreak

How Mpox Spreads

• Direct contact with rash, scabs, or body fluids
• Prolonged face-to-face respiratory contact
• Intimate contact (kissing, sex)
• Contact with contaminated clothing or bedding
• From infected animals
• From mother to fetus during pregnancy

People are contagious from symptom onset until full healing of the rash (2–4 weeks).

Symptoms

Symptoms usually develop within 3 weeks of exposure and may include:

• Rash (pimples or blisters progressing to scabs)
• Fever
• Chills
• Swollen lymph nodes
• Headache
• Muscle aches
• Exhaustion
• Sore throat or cough

Some people may only have a rash.

Treatment

There is no specific cure, but many recover without treatment. Antiviral medications used for smallpox may be recommended for:

• Immunocompromised individuals
• Pregnant people
• Young children
• People with certain skin conditions

Isolation is recommended until the rash fully heals.

Prevention

Vaccination

JYNNEOS vaccine is available for people at increased risk. Two doses are given 4 weeks apart for optimal protection.

Additional Prevention Steps

• Avoid close contact with infected individuals
• Do not share bedding, clothing, or utensils
• Practice good hand hygiene
• Clean and disinfect contaminated surfaces

Source: Centers for Disease Control and Prevention (CDC)

What Is MRSA?

MRSA stands for methicillin-resistant Staphylococcus aureus. It is a type of staph bacteria that has become resistant to several commonly used antibiotics, making infections harder to treat.

There are two main types:

• Hospital-associated MRSA (HA-MRSA): Occurs in healthcare settings such as hospitals and nursing homes.
• Community-associated MRSA (CA-MRSA): Occurs in otherwise healthy people, often spread through close skin-to-skin contact (e.g., athletes in contact sports like football or wrestling).

How Does MRSA Spread?

• Direct contact with infected wounds
• Sharing personal items (towels, razors, clothing)
• Contact with contaminated surfaces

Symptoms

MRSA most commonly causes skin infections, which may look like:

• Red, swollen, painful bumps
• Warm skin
• Pus or drainage
• Fever (in more serious infections)

If untreated, MRSA can spread to the bloodstream, lungs, or other organs.

Treatment

• Draining the infection
• Antibiotics (selected based on resistance testing)

Early medical evaluation is important if a wound appears infected

Prevention

• Practice good hand hygiene
• Keep cuts and scrapes clean and covered
• Avoid contact with other people’s wounds or bandages
• Do not share personal items
• Wash towels, clothing, and bedding in hot water with bleach when possible

Source: Centers for Disease Control and Prevention (CDC)

The nervous system includes the brain, spinal cord, and nerves. It controls movement, speech, breathing, memory, emotions, and learning.

When the nervous system is affected, symptoms may include:

• Difficulty moving or walking
• Trouble speaking or swallowing
• Memory loss
• Mood changes
• Seizures
• Loss of sensation

There are more than 600 neurologic disorders.

Major Types of Neurologic Diseases

• Genetic disorders: e.g., Huntington’s disease, muscular dystrophy
• Developmental disorders: e.g., spina bifida
• Degenerative diseases: e.g., Parkinson’s disease, Alzheimer’s disease
• Vascular diseases: e.g., stroke
• Traumatic injuries: brain and spinal cord injuries
• Seizure disorders: e.g., epilepsy
• Cancers: brain tumors
• Infections: meningitis

Early diagnosis and treatment can improve outcomes in many neurologic conditions.

Overview

Pets provide companionship, emotional support, and joy — but they also require consistent care.

Before Getting a Pet

Consider:

• Time commitment
• Financial responsibility
• Allergies
• Lifestyle compatibility
• Who will provide daily care

Warning Signs Your Pet Needs Veterinary Care

Contact a veterinarian if your pet shows:

• Loss of appetite
• Excessive thirst
• Sudden weight gain or loss
• Behavioral changes
• Lethargy
• Difficulty standing or walking
• Unusual lumps

Regular veterinary checkups help detect health problems early.

What Is Polio?

Polio (poliomyelitis) is a contagious disease caused by the poliovirus. The virus attacks the nervous system and, in severe cases, can cause lifelong paralysis.

Due to vaccination, polio is now rare in the United States, but it still exists in some parts of the world.

How Does Polio Spread?

Poliovirus spreads through:

• Contact with infected stool
• Respiratory droplets from coughing or sneezing
• Contaminated food or objects

People can spread the virus even if they have no symptoms.

Who Is at Risk?

• Children under age 5
• Unvaccinated individuals of any age
• Travelers to areas where polio is present

Symptoms

Most people have no symptoms. About 1 in 4 infected individuals experience flu-like symptoms:

• Fever
• Sore throat
• Fatigue
• Nausea
• Headache
• Stomach pain

Rarely, polio can cause:

• Meningitis
• Muscle weakness
• Paralysis (which may affect breathing muscles)

Overview

PPS affects some polio survivors 15–40 years after recovery.

Symptoms include:

• New muscle weakness
• Muscle wasting
• Fatigue
• Joint pain
• Scoliosis

PPS is not contagious but can significantly impact daily life.

Treatment

There is no cure for polio or PPS. Management may include:

• Physical or occupational therapy
• Pain management
• Ventilatory support (if needed)
• Mobility aids
• Lifestyle adjustments

Prevention

Vaccination is the most effective prevention.

Two vaccines exist:

• Inactivated poliovirus vaccine (IPV) – injection (used in the U.S.)
• Oral poliovirus vaccine (OPV) – used in many countries

Handwashing with soap and water also helps prevent spread (alcohol-based sanitizers do not kill poliovirus).

Source: Centers for Disease Control and Prevention (CDC)

Reye syndrome is a rare but serious condition that affects the brain and liver, typically following a viral illness. It most commonly affects children and teenagers.

Symptoms

Symptoms can develop quickly and include:

• Persistent vomiting
• Lethargy
• Irritability or personality changes
• Confusion or delirium
• Seizures
• Loss of consciousness

Reye syndrome is a medical emergency. Immediate treatment is critical to prevent brain damage or death.

Cause and Risk Factors

The exact cause is unknown. However, research has shown that aspirin use during viral illnesses increases risk in children and teens. For this reason, aspirin is generally not recommended for young patients unless specifically directed by a health care provider.

Treatment

There is no cure. Treatment focuses on:

• Reducing brain swelling
• Supporting breathing
• Stabilizing metabolic function

With prompt care, outcomes improve significantly.

Source: National Institute of Neurological Disorders and Stroke (NINDS)

What Is Smallpox?

Smallpox is a serious infectious disease caused by the Variola major virus. Historically, it was one of the deadliest diseases in human history.

A global vaccination campaign led to the eradication of smallpox in 1977, making it the first disease eliminated worldwide. Today, small amounts of the virus remain stored in secure research laboratories.

Although naturally occurring smallpox no longer exists, public health experts remain concerned about the possibility of its use in bioterrorism.

How Smallpox Spreads

• Respiratory droplets
• Direct contact with infected bodily fluids or contaminated materials

Symptoms

Symptoms begin with flu-like illness:

• High fever
• Fatigue
• Headache
• Backache

A few days later, a distinctive rash develops:

• Flat red sores
• Lesions that progress to pus-filled blisters
• Scabbing and eventual scarring

Treatment

There is no specific cure for smallpox. Supportive care includes:

• Fluids
• Fever reducers
• Pain control

Most people recover, but some cases can be fatal. Survivors often have permanent scarring.

Prevention

Routine vaccination in the U.S. stopped in 1972. The smallpox vaccine is still available for:

• Military personnel
• Laboratory workers
• Certain high-risk groups

Because the vaccine can cause side effects, it is reserved for those at highest risk.

Source: Centers for Disease Control and Prevention (CDC)

What Is a Sore Throat?

A sore throat refers to pain, scratchiness, or irritation of the pharynx (throat). It can affect swallowing or speaking.

Common Causes

Most sore throats are caused by viral infections, including:

• Colds
• Flu

Other causes include:

• Allergies
• Infectious mononucleosis
• Smoking
• Strep throat
• Tonsillitis

Treatment

Treatment depends on the cause:

• Lozenges
• Warm fluids
• Gargling salt water
• Over-the-counter pain relievers

Important: Children should not take aspirin due to the risk of Reye syndrome.

If symptoms last more than a few days or include high fever or difficulty swallowing, seek medical care.

Common Illnesses

Toddlers frequently experience:

• Colds
• Fevers
• Minor infections

It can be difficult to tell what is serious. Parents should learn the warning signs of more serious illness. Trust your instincts — if you are concerned about your child, contact your health care provider.

Importance of Well-Child Visits

Routine checkups are essential for:

• Monitoring growth and development
• Administering recommended vaccines
• Screening for developmental or health concerns
• Providing guidance on nutrition and safety

Preventive care helps identify and manage issues early.

Travel can expose you to unfamiliar bacteria, viruses, parasites, and environmental conditions.

Travel-Related Risks

• Deep vein thrombosis (DVT) after long flights
• Traveler’s diarrhea
• Food poisoning
• Mosquito-borne diseases

Food and Water Safety

When traveling to developing regions:

• Drink bottled or purified water
• Avoid ice unless made with purified water
• Eat only fully cooked, hot foods
• Avoid raw or unpeeled fruits and vegetables

Vaccines and Preventive Medicines

You may need:

• Vaccinations
• Preventive medications (such as malaria prevention)

Recommendations depend on:

• Destination
• Season
• Your age and health
• Prior immunizations

See a health care provider 4–6 weeks before travel, since many vaccines require time to become effective.

Source: Centers for Disease Control and Prevention (CDC)

What Is Valley Fever?

Valley Fever is an infection caused by the fungus Coccidioides. The fungus lives in dry soil, especially in the southwestern United States.

You become infected by inhaling fungal spores from the air. It does not spread from person to person.

Who Is at Risk?

Anyone can get Valley Fever, but higher-risk groups include:

• Adults over age 60
• Construction and agricultural workers
• Military personnel in field training
• African Americans and Asians
• Pregnant women (third trimester)
• People with weakened immune systems

Symptoms

Many infections are mild or symptom-free.

If symptoms occur, they may include:

• Fever
• Cough
• Headache
• Rash
• Muscle aches
• Fatigue

Most people recover within weeks to months. A small number may develop:

• Chronic lung infection
• Widespread (disseminated) infection

Diagnosis and Treatment

Diagnosis is made through:

• Blood tests
• Testing of body fluids or tissue

Treatment depends on severity:

• Mild cases may not require treatment
• More severe cases require antifungal medication

Early medical evaluation is important if symptoms persist.

Source: Centers for Disease Control and Prevention (CDC)

What Are Viruses?

Viruses are extremely small infectious agents made of genetic material (DNA or RNA) surrounded by a protein coating. They cannot survive or reproduce on their own. Instead, they must invade living cells.

Although billions of viruses exist worldwide, only a small number infect humans. Viral infections can cause illnesses such as:

• The common cold
• Influenza (flu)
• COVID-19
• HIV

How Do Viruses Spread?

Viruses spread in several ways:

• Through respiratory droplets or tiny particles released when an infected person coughs, sneezes, talks, or breathes
• By touching contaminated surfaces and then touching your eyes, nose, or mouth
• From a pregnant parent to a baby during pregnancy
• Through contaminated food or water
• Through insect or animal bites
• Through sexual contact

How Do Viruses Cause Disease?

Viruses act like biological hijackers. They invade healthy cells and use them to replicate (make copies of themselves).

During this process, infected cells may be:

• Damaged
• Destroyed
• Altered

This damage can lead to symptoms ranging from mild to severe. In some cases, your immune system clears the infection without noticeable symptoms.

Many viruses target specific cell types:

• Hepatitis viruses infect liver cells
• HIV infects immune system cells

Treatment of Viral Infections

For most viral infections:

• Treatment focuses on relieving symptoms
• Your immune system clears the infection over time

Some viruses can be treated with antiviral medications

Important: Antibiotics do not work against viral infections.

Prevention

Viral infections can often be prevented through:

• Vaccination
• Proper handwashing
• Safe food handling
• Cleaning contaminated surfaces
• Avoiding contact with wild animals
• Using insect repellent in high-risk areas
• Practicing safe sex
• Avoiding close contact with sick individuals

What Are Vaccines?

Vaccines are medical products given as:

• Injections (shots)
• Oral liquids or pills
• Nasal sprays

They train the immune system to recognize and fight harmful germs (viruses or bacteria).

Some vaccines contain:

• Weakened germs
• Killed germs
• Parts of germs
• Instructions (such as mRNA) that help your cells make a harmless protein to trigger immunity

All vaccine types stimulate an immune response that creates lasting protection, known as immunity.

Why Vaccinate Children?

Babies are born with immune systems, but they are not strong enough to fight certain serious diseases. Vaccines:

• Protect children from dangerous illnesses
• Prevent long-term complications
• Reduce hospitalizations
• Prevent deaths

Vaccination also creates community immunity, which protects:

• Infants too young to be vaccinated
• People with weakened immune systems
• Individuals allergic to certain vaccine components

Are Childhood Vaccines Safe?

Yes. Vaccines undergo extensive safety testing before approval in the United States.

Large scientific studies have shown no link between vaccines and autism spectrum disorder (ASD).

Do Vaccines Overload the Immune System?

No. A child’s immune system encounters thousands of germs daily. The number of antigens in vaccines is tiny compared to everyday exposure.

When Should Children Be Vaccinated?

Vaccines are given during well-child visits according to the immunization schedule published by the CDC. Following the schedule ensures children build protection at the safest and most effective time.

Lung Diseases

Your lungs deliver oxygen to your bloodstream and remove carbon dioxide from your body. On average, you breathe nearly 25,000 times per day.

Lung disease refers to many disorders that affect breathing. These include:

• Asthma
• COPD
• Influenza
• Pneumonia
• Tuberculosis
• Lung cancer

If grouped together, lung diseases are the third leading cause of death in the United States.

Some lung diseases can progress to respiratory failure.

Source: U.S. Department of Health and Human Services, Office on Women’s Health

Why Vaccines Matter

Vaccines protect against serious and sometimes life-threatening diseases. They work by teaching your immune system to recognize and fight germs.

Getting immunity from a vaccine is safer than getting immunity from the disease itself.

Side Effects

Most vaccine side effects are mild and temporary:

• Sore arm
• Fatigue
• Mild fever

These often indicate your immune system is building protection. Serious side effects are very rare but may include severe allergic reactions. There is no scientific evidence linking vaccines to autism spectrum disorder (ASD).

How Vaccines Are Tested

Vaccine development follows strict safety standards:

1. Laboratory Testing

   Initial testing in labs evaluates safety before human trials.

2. Clinical Trials

   Conducted in phases:

   • Small groups (20–100 volunteers)
   • Larger groups (hundreds to thousands)

   Researchers evaluate:

   • Safety
   • Effective dose
   • Immune response
   • Overall effectiveness
3. FDA Review

   The FDA evaluates all safety and effectiveness data before approval.

4. Ongoing Monitoring

   After approval:

   • Each vaccine batch is tested
   • Manufacturing facilities are inspected
   • Safety monitoring systems track potential side effects

These measures ensure vaccines in the United States meet high standards for safety and quality. Vaccines protect not only individuals but entire communities.