This infection of the intestine causes diarrhea. Learn the symptoms, treatments and ways to help prevent it.
Disease
Shin splints
This pain along the shin bone is common in runners, dancers and military trainees. Learn how to prevent shin splints.
Disease
Shingles
Learn more about symptoms, causes, treatment and vaccine prevention of this painful condition affecting the nerves.
Disease
Short bowel syndrome
This digestive condition happens when part of the small intestine is missing or damaged, either at birth or after surgery. The syndrome keeps you from absorbing needed nutrients.
Disease
Sick sinus syndrome
This heart rhythm disorder causes slow, paused or irregular heartbeats. Learn the symptoms and how it's treated.
Disease
Sickle cell anemia
Learn about the symptoms, causes and treatment of this inherited blood disorder that, in the United States, is more common among Black people.
Disease
Sinus headaches
Sinus headaches are often to blame for headache with facial pain — but that pain might actually be a migraine.
Disease
Sjogren's syndrome
If you're bothered by dry eyes and mouth, talk to your doctor about whether you have the autoimmune condition Sjogren's syndrome.
Disease
Skin cancer
Learn about skin cancer, including basal cell carcinoma and squamous cell carcinoma. Find out about symptoms, treatments and ways to lower your risk.
Disease
Skull base tumors
Skull base tumors are abnormal growths at the base of the skull that can be benign or cancerous and cause symptoms such as headaches, dizziness and nosebleeds. Treatment may include surgery, radiation or careful monitoring.
Disease
Sleep apnea
Snoring loudly could be an indication of sleep apnea, a disorder in which breathing stops and starts repeatedly during sleep.
Disease
Sleep disorders
Common types include insomnia, sleep apnea, restless legs syndrome and narcolepsy. Other types include nightmare disorder and sleep terrors.