DEFINITION Schizophrenia is a severe brain disorder in which people interpret reality abnormally. Schizophrenia may result in some combination of hallucinations, delusions, and extremely disordered thinking and behavior. Contrary to popular belief, schizophrenia isn’t a split personality or multiple personality.…
DEFINITION Schizoid personality disorder is an uncommon condition in which people avoid social activities and consistently shy away from interaction with others. It affects more males than females. If you have schizoid personality disorder, you may be seen as a…
DEFINITION Schizoaffective disorder is a condition in which a person experiences a combination of schizophrenia symptoms — such as hallucinations or delusions — and mood disorder symptoms, such as mania or depression. Schizoaffective disorder is not as well understood or…
DEFINITION Scarlet fever is a bacterial illness that develops in some people who have strep throat. Also known as scarlatina, scarlet fever features a bright red rash that covers most of the body. Scarlet fever is almost always accompanied by…
DEFINITION Sarcoma is a type of cancer that can occur in various locations in your body. Sarcoma is the general term for a broad group of cancers that includes tumors that form in the bones and in the soft (also…
DEFINITION Sarcoidosis is the growth of tiny collections of inflammatory cells in different parts of your body — most commonly the lungs, lymph nodes, eyes and skin. Doctors believe sarcoidosis results from the body’s immune system responding to an unknown…
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 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 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 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 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 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.…