MedlinePlus is a service of the National Library of Medicine (NLM), the world's largest medical library, which is part of the National Institutes of Health (NIH). It was built as an online health information resource for patients and their families and friends.
MedlinePlus presents high-quality, easy to understand, relevant health and wellness information that is trusted.
Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales. You usually get the patches on your elbows, knees, scalp, ...
What are pubic lice? Pubic lice (also called crabs) are tiny insects which usually live in the pubic or genital area of humans. They are also sometimes ...
What is a pulmonary embolism (PE)? A pulmonary embolism (PE) is a sudden blockage in a lung artery. It usually happens when a blood clot breaks loose and ...
What is pulmonary hypertension? Pulmonary hypertension, sometimes called PH, is a serious condition that affects the blood vessels in the lungs. It develops ...
What is pulmonary rehabilitation? Pulmonary rehabilitation, also known as pulmonary rehab or PR, is a program for people who have chronic (ongoing) breathing ...
Radiation is a type of energy. People are exposed to small amounts of radiation every day from sources such as sunlight. A radiation emergency would involve larger ...
What is radiation? Radiation is energy. It travels in the form of energy waves or high-speed particles. Radiation can occur naturally or be man-made. ...
What is radon? Radon is a naturally occurring radioactive gas. It is invisible and has no odor or taste. It comes from the normal decay of uranium and ...
What is Raynaud phenomenon? Raynaud phenomenon is a condition that affects your blood vessels (the tubes that your blood flows through). It causes your ...
What are reflux (GER) and GERD? The esophagus is the tube that carries food from your mouth to your stomach. If your child has reflux, his or her stomach ...
What are reflux and GERD? The esophagus is the tube that carries food from your mouth to your stomach. If your baby has reflux, his or her stomach contents ...
What is rehabilitation? Rehabilitation is care that can help you get back, keep, or improve abilities that you need for daily life. These abilities may ...
What are reproductive hazards? Reproductive hazards are substances that affect the reproductive health of men or women. They also include substances that ...
What is respiratory failure? Respiratory failure is a condition in which your blood doesn't have enough oxygen or has too much carbon dioxide. Sometimes ...
What is respiratory syncytial virus (RSV)? Respiratory syncytial virus, or RSV, is a common respiratory virus. It usually causes mild, cold-like symptoms. ...
Restless legs syndrome (RLS) causes a powerful urge to move your legs. Your legs become uncomfortable when you are lying down or sitting. Some people describe ...
What is rheumatoid arthritis? Rheumatoid arthritis (RA) is a form of arthritis that causes pain, swelling, and stiffness in your joints. RA is an autoimmune ...
What is a rotator cuff? Your rotator cuff is part of your shoulder joint. It's a group of muscles and tendons that holds the top part of your upper arm ...
Around 15% of people in the United States live in rural areas. There are many different reasons why you might choose to live in a rural community. You may want ...
What are opioids? Opioids, sometimes called narcotics, are a type of drug. They include strong prescription pain relievers such as oxycodone, hydrocodone, ...
