COVID-19 (Coronavirus Disease 2019)

COVID-19 (coronavirus disease 2019) is an illness caused by a virus. This virus is a coronavirus called SARS-CoV-2. It spreads when a person who has the infection breathes out droplets and very small particles that contain the virus. On this page, you'll find links to resources on important issues such as symptoms, risks, and how you can protect yourself and your family.

We also have pages on:

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

Diarrhea

What is diarrhea?

Diarrhea is loose, watery stools (bowel movements). You have diarrhea if you have loose stools three or more times in one day. Acute diarrhea is diarrhea that lasts a short time. It is a common problem. It usually lasts about one or two days, but it may last longer. Then it goes away on its own.

Diarrhea lasting more than a few days may be a sign of a more serious problem. Chronic diarrhea -- diarrhea that lasts at least four weeks -- can be a symptom of a chronic disease. Chronic diarrhea symptoms may be continual, or they may come and go.

What causes diarrhea?

The most common causes of diarrhea include:

• Bacteria from contaminated food or water
• Viruses such as the flu, norovirus, or rotavirus . Rotavirus is the most common cause of acute diarrhea in children.
• Parasites, which are tiny organisms found in contaminated food or water
• Medicines such as antibiotics, cancer drugs, and antacids that contain magnesium
• Food intolerances and sensitivities, which are problems digesting certain ingredients or foods. An example is lactose intolerance.
• Diseases that affect the stomach, small intestine, or colon, such as Crohn's disease
• Problems with how the colon functions, such as irritable bowel syndrome

Some people also get diarrhea after stomach surgery, because sometimes the surgeries can cause food to move through your digestive system more quickly.

Sometimes no cause can be found. If your diarrhea goes away within a few days, finding the cause is usually not necessary.

Who is at risk for diarrhea?

People of all ages can get diarrhea. On average, adults In the United States have acute diarrhea once a year. Young children have it an average of twice a year.

People who visit developing countries are at risk for traveler's diarrhea. It is caused by consuming contaminated food or water.

What other symptoms might I have with diarrhea?

Other possible symptoms of diarrhea include:

• Cramps or pain in the abdomen
• An urgent need to use the bathroom
• Loss of bowel control

If a virus or bacteria is the cause of your diarrhea, you may also have a fever, chills, and bloody stools.

Diarrhea can cause dehydration, which means that your body does not have enough fluid to work properly. Dehydration can be serious, especially for children, older adults, and people with weakened immune systems.

When do I need to see a health care provider for diarrhea?

Although it is usually not harmful, diarrhea can become dangerous or signal a more serious problem. Contact your health care provider if you have:

• Signs of dehydration
• Diarrhea for more than 2 days, if you are an adult. For children, contact the provider if it lasts more than 24 hours.
• Severe pain in your abdomen or rectum (for adults)
• A fever of 102 degrees or higher
• Stools containing blood or pus
• Stools that are black and tarry

If children have diarrhea, parents or caregivers should not hesitate to call a health care provider. Diarrhea can be especially dangerous in newborns and infants.

How is the cause of diarrhea diagnosed?

To find the cause of diarrhea, your health care provider may:

• Do a physical exam
• Ask about any medicines you are taking
• Test your stool or blood to look for bacteria, parasites, or other signs of disease or infection
• Ask you to stop eating certain foods to see whether your diarrhea goes away

If you have chronic diarrhea, your health care provider may perform other tests to look for signs of disease.

What are the treatments for diarrhea?

Diarrhea is treated by replacing lost fluids and electrolytes to prevent dehydration. Depending on the cause of the problem, you may need medicines to stop the diarrhea or treat an infection.

Adults with diarrhea should drink water, fruit juices, sports drinks, sodas without caffeine, and salty broths. As your symptoms improve, you can eat soft, bland food.

Children with diarrhea should be given oral rehydration solutions to replace lost fluids and electrolytes.

Can diarrhea be prevented?

Two types of diarrhea can be prevented - rotavirus diarrhea and traveler's diarrhea. There are vaccines for rotavirus. They are given to babies in two or three doses.

You can help prevent traveler's diarrhea by being careful about what you eat and drink when you are in developing countries:

• Use only bottled or purified water for drinking, making ice cubes, and brushing your teeth
• If you do use tap water, boil it or use iodine tablets
• Make sure that the cooked food you eat is fully cooked and served hot
• Avoid unwashed or unpeeled raw fruits and vegetables

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Emphysema

What is emphysema?

Emphysema is a type of COPD (chronic obstructive pulmonary disease). COPD is a group of lung diseases that make it hard to breathe and get worse over time. The other main type of COPD is chronic bronchitis. Most people with COPD have both emphysema and chronic bronchitis, but how severe each type is can be different from person to person.

Emphysema affects the air sacs in your lungs. Normally, these sacs are elastic or stretchy. When you breathe in, each air sac fills up with air, like a small balloon. When you breathe out, the air sacs deflate, and the air goes out.

In emphysema, the walls between many of the air sacs in the lungs are damaged. This causes the air sacs to lose their shape and become floppy. The damage also can destroy the walls of the air sacs, leading to fewer and larger air sacs instead of many tiny ones. This makes it harder for your lungs to move oxygen in and carbon dioxide out of your body.

What causes emphysema?

The cause of emphysema is usually long-term exposure to irritants that damage your lungs and the airways. In the United States, cigarette smoke is the main cause. Pipe, cigar, and other types of tobacco smoke can also cause emphysema, especially if you inhale them.

Exposure to other inhaled irritants can contribute to emphysema. These include secondhand smoke, air pollution, and chemical fumes or dusts from the environment or workplace.

Rarely, a genetic condition called alpha-1 antitrypsin deficiency can play a role in causing emphysema.

Who is at risk for emphysema?

The risk factors for emphysema include:

• Smoking. This the main risk factor. Up to 75% of people who have emphysema smoke or used to smoke.
• Long-term exposure to other lung irritants, such as secondhand smoke, air pollution, and chemical fumes and dusts from the environment or workplace.
• Age. Most people who have emphysema are at least 40 years old when their symptoms begin.
• Genetics. This includes alpha-1 antitrypsin deficiency, which is a genetic condition. Also, smokers who get emphysema are more likely to get it if they have a family history of COPD.

What are the symptoms of emphysema?

At first, you may have no symptoms or only mild symptoms. As the disease gets worse, your symptoms usually become more severe. They can include:

• Frequent coughing or wheezing
• A cough that produces a lot mucus
• Shortness of breath, especially with physical activity
• A whistling or squeaky sound when you breathe
• Tightness in your chest

Some people with emphysema get frequent respiratory infections such as colds and the flu. In severe cases, emphysema can cause weight loss, weakness in your lower muscles, and swelling in your ankles, feet, or legs.

How is emphysema diagnosed?

Your health care provider may use many tools to make a diagnosis:

• A medical history, which includes asking about your symptoms
• A family history
• Other tests, such as lung function tests, a chest x-ray or CT scan, and blood tests

What are the treatments for emphysema?

There is no cure for emphysema. However, treatments can help with symptoms, slow the progress of the disease, and improve your ability to stay active. There are also treatments to prevent or treat complications of the disease. Treatments include:

• Lifestyle changes, such as
  • Quitting smoking if you are a smoker. This is the most important step you can take to treat emphysema.
  • Avoiding secondhand smoke and places where you might breathe in other lung irritants
  • Ask your health care provider for an eating plan that will meet your nutritional needs. Also ask about how much physical activity you can do. Physical activity can strengthen the muscles that help you breathe and improve your overall wellness.
• Medicines, such as
  • Bronchodilators, which relax the muscles around your airways. This helps open your airways and makes breathing easier. Most bronchodilators are taken through an inhaler. In more severe cases, the inhaler may also contain steroids to reduce inflammation.
  • Vaccines for the flu and pneumococcal pneumonia, since people with emphysema are at higher risk for serious problems from these diseases
  • Antibiotics if you get a bacterial or viral lung infection
• Oxygen therapy, if you have severe emphysema and low levels of oxygen in your blood. Oxygen therapy can help you breathe better. You may need extra oxygen all the time or only at certain times.
• Pulmonary rehabilitation, which is a program that helps improve the well-being of people who have chronic breathing problems. It may include
  • An exercise program
  • Disease management training
  • Nutritional counseling
  • Psychological counseling
• Surgery, usually as a last resort for people who have severe symptoms that have not gotten better with medicines. There are surgeries to
  • Remove damaged lung tissue
  • Remove large air spaces (bullae) that can form when air sacs are destroyed. The bullae can interfere with breathing.
  • Do a lung transplant. This is might be an option if you have very severe emphysema.

If you have emphysema, it's important to know when and where to get help for your symptoms. You should get emergency care if you have severe symptoms, such as trouble catching your breath or talking. Call your health care provider if your symptoms are getting worse or if you have signs of an infection, such as a fever.

Can emphysema be prevented?

Since smoking causes most cases of emphysema, the best way to prevent it is to not smoke. It's also important to try to avoid lung irritants such as secondhand smoke, air pollution, chemical fumes, and dusts.

NIH: National Heart, Lung, and Blood Institute

Heart Diseases

What is heart disease?

Heart disease is a general term that includes many types of heart problems. It's a type of cardiovascular disease, which means heart and blood vessel disease.

Heart disease is the leading cause of death in the United States, but there are ways to prevent and manage many types of heart disease.

What are the types of heart disease?

There are many different types of heart disease. Some you may be born with, called congenital heart disease. Other types develop during your lifetime.

Coronary artery disease (also called coronary heart disease) is the most common type of heart disease. It happens slowly over time when a sticky substance called plaque builds up in the arteries that supply your heart muscle with blood. The plaque narrows or blocks blood flow to the heart muscle and can lead to other heart problems:

• Angina - chest pain from lack of blood flow
• Heart attacks - when part of the heart muscle dies from loss of blood flow
• Heart failure - when your heart can't pump enough blood to meet your body's needs
• Arrhythmia - a problem with the rate or rhythm of your heartbeat

Other types of heart diseases may affect your heart valves or heart muscle (cardiomyopathy).

What causes heart diseases?

The causes of heart disease depend on the type of disease. Some possible causes include lifestyle, genetics, infections, medicines, and other diseases.

Who is more likely to develop heart diseases?

There are many different factors that can make you more likely to develop heart disease. Some of these factors you can change, but others you cannot.

• Age. Your risk of heart disease goes up as you get older.
• Sex. Some factors may affect heart disease risk differently in women than in men.
• Family history and genetics. A family history of early heart disease raises your risk. And research has shown that some genes are linked to a higher risk of certain heart diseases.
• Race/ethnicity. Heart disease is the leading cause of death in most racial and ethnic groups in the United States. However, certain groups have higher risks than others. This includes Black people, White people, and American Indian/Alaska Native people.
• Lifestyle habits. Over time, unhealthy lifestyle habits can raise your risk of heart disease. These can include:
  • Eating a diet high in saturated fats, refined carbohydrates, and salt.
  • Not getting enough physical activity.
  • Drinking too much alcohol.
  • Smoking and exposure to secondhand smoke.
  • Too much stress.
• Having other medical conditions can raise your risk of heart diseases. These conditions include:
  • High blood pressure.
  • High cholesterol levels.
  • Diabetes.
  • Obesity.
  • Autoimmune and inflammatory diseases.
  • Chronic kidney disease.
  • Metabolic syndrome.

What are the symptoms of heart disease?

Your symptoms will depend on the type of heart disease you have. You may not have symptoms at first. In some cases, you may not know you have heart disease until you have a complication such as a heart attack.

How are heart diseases diagnosed?

To find out if you have heart disease, your health care provider will:

• Ask about your medical history, including your symptoms
• Ask about your family health history, including relatives who have had heart disease
• Do a physical exam
• Likely run heart tests and blood tests

In some cases, your provider may refer you to a cardiologist (a doctor who specializes in heart diseases) for tests, diagnosis, and care.

What are the treatments for heart disease?

Treatment plans for heart disease depend on the type of heart disease you have, how serious your symptoms are, and what other health conditions you have. Possible treatments may include:

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

Can heart diseases be prevented?

You may be able to lower your risk of certain heart diseases by making heart-healthy lifestyle changes and managing any other medical conditions you have.

NIH: National Heart, Lung, and Blood Institute

HIV and Infections

Having HIV/AIDS weakens your body's immune system. It destroys the white blood cells that fight infection. This puts you at risk for opportunistic infections (OIs). OIs are serious infections that take advantage of your weak immune system. These infections are less common and less severe in healthy people.

There are many types of OIs:

• Bacterial infections, including tuberculosis and a serious related disease, Mycobacterium avium complex (MAC)
• Viral infections, such as cytomegalovirus (CMV) and hepatitis C
• Fungal infections, like yeast infections, cryptococcal meningitis, pneumocystis carinii pneumonia (PCP) and histoplasmosis
• Parasitic infections, such as crypto (cryptosporidiosis) and toxo (toxoplasmosis)

Having HIV/AIDS can make infections harder to treat. People with HIV/AIDS are also more likely to have complications from common illnesses such as the flu.

You can help prevent infections by taking your HIV/AIDS medicines. Other things that can help include practicing safe sex, washing your hands well and often, and cooking your food thoroughly.