DEFINITION Radiation enteritis is inflammation of the intestines that occurs after radiation therapy. Radiation enteritis causes diarrhea, nausea, vomiting and stomach cramps in people receiving radiation aimed at the abdomen, pelvis or rectum. Radiation enteritis is most common in people…
DEFINITION Rabies is a deadly virus spread to people from the saliva of infected animals. The rabies virus is usually transmitted through a bite. Animals most likely to transmit rabies in the United States include bats, coyotes, foxes, raccoons and…
DEFINITION Rectal prolapse occurs when part of the large intestine’s lowest section (rectum) slips outside the muscular opening at the end of the digestive tract (anus). The prolapsed rectum can cause fecal incontinence. Surgery is usually needed to treat rectal…
DEFINITION A rectovaginal fistula is an abnormal connection between the lower portion of your large intestine — your rectum — and your vagina. Contents of your bowel can leak through the fistula, meaning you might pass gas or stool through…
DEFINITION 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.…
DEFINITION 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…
DEFINITION 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…
DEFINITION 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…
DEFINITION The retina is a thin layer of tissue on the inside back wall of your eye. It contains millions of light-sensitive cells and other nerve cells that receive and organize visual information. Your retina sends this information to your…
DEFINITION 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…
DEFINITION Renal artery stenosis is the narrowing of one or more arteries that carry blood to your kidneys (renal arteries). Narrowing of the arteries prevents normal amounts of oxygen-rich blood from reaching your kidneys. Your kidneys need adequate blood flow…
DEFINITION Recurrent breast cancer is breast cancer that comes back after initial treatment. Although the initial treatment is aimed at eliminating all cancer cells, a few may have evaded treatment and survived. These undetected cancer cells multiply, becoming recurrent breast…