DEFINITION Stage 4 prostate cancer is cancer that begins in the prostate and grows to involve nearby organs or spreads to other areas of the body. Stage 4 prostate cancer is an uncommon diagnosis. Most cases of prostate cancer are…
DEFINITION Squamous cell carcinoma of the skin is a common form of skin cancer that develops in the thin, flat squamous cells that make up the outer layer of the skin. Squamous cell carcinoma of the skin is usually not…
DEFINITION Stomach polyps are masses of cells that form on the inside lining of your stomach. Stomach polyps, also called gastric polyps, are rare. Stomach polyps usually don’t cause any signs or symptoms. The polyps are most often discovered when…
DEFINITION Stickler syndrome is a genetic disorder that can cause serious vision, hearing and joint problems. Also known as hereditary progressive arthro-ophthalmopathy, Stickler syndrome is usually diagnosed during infancy or childhood. Children who have Stickler syndrome often have distinctive facial…
DEFINITION A sprained ankle is an injury that occurs when you roll, twist or turn your ankle in an awkward way. This can stretch or tear the tough bands of tissue (ligaments) that help hold your ankle bones together. Ligaments…
DEFINITION Spinal headaches occur in up to 40 percent of those who undergo a spinal tap (lumbar puncture) or spinal anesthesia. Both procedures require a puncture of the tough membrane that surrounds the spinal cord and, in the lower spine,…
DEFINITION Sjogren’s (SHOW-grins) syndrome is a disorder of your immune system identified by its two most common symptoms — dry eyes and a dry mouth. Sjogren’s syndrome often accompanies other immune system disorders, such as rheumatoid arthritis and lupus. In…
DEFINITION Sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and starts. You may have sleep apnea if you snore loudly and you feel tired even after a full night’s sleep. There are two main types…
DEFINITION Central sleep apnea is a disorder in which your breathing repeatedly stops and starts during sleep. Central sleep apnea occurs because your brain doesn’t send proper signals to the muscles that control your breathing. This condition is different from…
DEFINITION Obstructive sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and starts during sleep. Several types of sleep apnea exist, but the most common type is obstructive sleep apnea, which occurs when your throat muscles…
DEFINITION Sleep disorders are changes in sleeping patterns or habits. Signs and symptoms of sleep disorders include excessive daytime sleepiness, irregular breathing or increased movement during sleep, difficulty sleeping, and abnormal sleep behaviors. A sleep disorder can affect your overall…
DEFINITION Sleep terrors are episodes of screaming, intense fear and flailing while still asleep. Also known as night terrors, sleep terrors often are paired with sleepwalking. Like sleepwalking, sleep terrors are considered a parasomnia — an undesired occurrence during sleep.…