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The cornea and lens of your eye helps you focus. Refractive errors are vision problems that happen when the shape of the eye keeps you from focusing well. ...
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 ...
The retina is a layer of tissue in the back of your eye that senses light and sends images to your brain. It provides the sharp, central vision needed for ...
The retina is a layer of tissue in the back of your eye that senses light and sends images to your brain. In the center of this nerve tissue is the macula. ...
Rett syndrome is a rare genetic disease that causes developmental and nervous system problems, mostly in girls. It's related to autism spectrum disorder. ...
Reye syndrome is a rare illness that can affect the blood, liver, and brain of someone who has recently had a viral infection. It always follows another illness. ...
What is the Rh factor? There are four major blood types: A, B, O, and AB. The types are based on substances found on your blood cells. Your blood type ...
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 ...
Rickets causes soft, weak bones in children. It usually occurs when they do not get enough vitamin D, which helps growing bones absorb the minerals calcium and ...
Rosacea is a long-term disease that affects your skin and sometimes your eyes. It causes redness and pimples. Rosacea is most common in women and people with ...
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 ...
Rotavirus is a virus that causes gastroenteritis. Symptoms include severe diarrhea, vomiting, fever, and dehydration. Almost all children in the U.S. are likely ...
Rubella is an infection caused by a virus. It is usually mild with fever and a rash. About half of the people who get rubella do not have symptoms. If you do ...
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, ...
You can't remove all the safety hazards from your life, but you can reduce them. To avoid many major hazards and prepare for emergencies: Keep emergency ...
