All Diseases

Restless legs syndrome (RLS) is a condition in which you have an uncontrollable urge to move your legs, usually due to leg discomfort.  It typically happens in the evenings or nights while you're sitting or lying down. Moving eases the unpleasant feeling temporarily.

Restless legs syndrome, now known as restless legs syndrome/Willis-Ekbom disease (RLS/WED), can begin at any age and generally worsens as you age. It can disrupt sleep — leading to daytime drowsiness — and make traveling difficult.

Simple self-care steps and lifestyle changes may help you. Medications also help many people with restless legs syndrome.

Retinal detachment describes an emergency situation in which a critical layer of tissue (the retina) at the back of the eye pulls away from the layer of blood vessels that provides it with oxygen and nourishment.

Retinal detachment leaves the retinal cells lacking oxygen. The longer retinal detachment goes untreated, the greater your risk of permanent vision loss in the affected eye.

Fortunately, retinal detachment often has symptoms that are clear warning signs. Early diagnosis and treatment of retinal detachment can save your vision. If you suspect you may have a retinal detachment, contact an eye specialist (ophthalmologist) as soon as warning signs appear.

Retinoblastoma is an eye cancer that begins in the retina — the sensitive lining on the inside of your eye. Retinoblastoma most commonly affects young children, but can rarely occur in adults.

Your retina is made up of nerve tissue that senses light as it comes through the front of your eye. The retina sends signals through your optic nerve to your brain, where these signals are interpreted as images.

A rare form of eye cancer, retinoblastoma is the most common form of cancer affecting the eye in children. Retinoblastoma may occur in one or both eyes.

A retractile testicle is a testicle that may move back and forth between the scrotum and the groin. When the retractile testicle is residing in the groin, it may be easily guided by hand into its proper position in the scrotum — the bag of skin hanging behind the penis — during a physical examination.

For most boys, the problem of a retractile testicle goes away sometime before or during puberty, the time when an out-of-place testicle moves to its correct location in the scrotum and stays there permanently.

About a quarter of the time, the retractile testicle stays up in the groin and is no longer movable. When this happens, the condition is called an ascending testicle.

Retrograde ejaculation occurs when semen enters the bladder instead of emerging through the penis during orgasm. Although you still reach sexual climax, you may ejaculate very little or no semen. This is sometimes called a dry orgasm. Retrograde ejaculation isn't harmful, but it can cause male infertility. Treatment for retrograde ejaculation is generally only needed to restore fertility.

Rett syndrome is a rare genetic disorder that affects the way the brain develops. It occurs almost exclusively in girls.

Most babies with Rett syndrome seem to develop normally at first, but symptoms surface after 6 months of age. Over time, children with Rett syndrome have increasing problems with movement, coordination and communication that may affect their ability to use their hands, communicate and walk.

Although there's no cure for Rett syndrome, potential treatments are being studied. Current Rett syndrome treatment focuses on improving movement and communication and providing care and support for affected children and their families.

Reye's (Ryes) syndrome is a rare but serious condition that causes swelling in the liver and brain. Reye's syndrome most often affects children and teenagers recovering from a viral infection, most commonly the flu or chickenpox.

Signs and symptoms such as confusion, seizures and loss of consciousness require emergency treatment. Early diagnosis and treatment of Reye's syndrome can save a child's life.

Aspirin has been linked with Reye's syndrome, so use caution when giving aspirin to children or teenagers. Though aspirin is approved for use in children older than age 2, children and teenagers recovering from chickenpox or flu-like symptoms should never take aspirin. Talk to your doctor if you have concerns.

Rheumatic fever is an inflammatory disease that can develop as a complication of inadequately treated strep throat or scarlet fever. Strep throat and scarlet fever are caused by an infection with group A streptococcus bacteria.

Rheumatic fever is most common in 5- to 15-year-old children, though it can develop in younger children and adults. Although strep throat is common, rheumatic fever is rare in the United States and other developed countries. However, rheumatic fever remains common in many developing nations.

Rheumatic fever can cause permanent damage to the heart, including damaged heart valves and heart failure. Treatments can reduce tissue damage from inflammation, lessen pain and other symptoms, and prevent the recurrence of rheumatic fever.

Rheumatoid arthritis is a chronic inflammatory disorder that typically affects the small joints in your hands and feet. Unlike the wear-and-tear damage of osteoarthritis, rheumatoid arthritis affects the lining of your joints, causing a painful swelling that can eventually result in bone erosion and joint deformity.

An autoimmune disorder, rheumatoid arthritis occurs when your immune system mistakenly attacks your own body's tissues. In addition to causing joint problems, rheumatoid arthritis sometimes can affect other organs of the body — such as the skin, eyes, lungs and blood vessels.

Although rheumatoid arthritis can occur at any age, it usually begins after age 40. The disorder is much more common in women.

Treatment focuses on controlling symptoms and preventing joint damage.

Rickets is the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency.

Vitamin D promotes the absorption of calcium and phosphorus from the gastrointestinal tract. A deficiency of vitamin D makes it difficult to maintain proper calcium and phosphorus levels in bones, which can cause rickets.

If a vitamin D or calcium deficiency causes rickets, adding vitamin D or calcium to the diet generally corrects any resulting bone problems for your child. Rickets due to a genetic condition may require additional medications or other treatment. Some skeletal deformities caused by rickets may need corrective surgery.