In the early stages of serotonin syndrome people may experience mild serotonin syndrome, which causes symptoms such as tremors, dizziness, and headache. Serotonin syndrome, or serotonin toxicity, is a ...

Subclavian steal syndrome is characterized by abnormal blood flow in the arteries. The condition has many potential causes, some of which can be serious without proper treatment. Subclavian steal ...

Sanfilippo syndrome, also known as mucopolysaccharidosis type III, is a rare life-threatening disorder that interferes with metabolism. While it doesn’t have a cure, some symptoms can be treated to ...

Kelly Wood, MD, is a board-certified endocrinologist with a special interest in osteoporosis and metabolic bone disease. Symptoms of Cushing's syndrome include a round face, weight gain, and muscle ...

What is Klippel-Feil syndrome? This bone disorder happens when two or more of the spinal bones in your neck are abnormally joined. This condition is present from birth, although mild cases might only ...

Superior mesenteric artery syndrome is a rare type of compression of the small intestine. It’s a treatable condition, but a delayed diagnosis can lead to more severe symptoms or even death. SMA ...

Susac syndrome is a rare immune-mediated condition that affects the brain, eyes, and ears. Treatment involves taking medication to suppress the immune system. Share on Pinterest Getty Images/FG Trade ...

Stiff person syndrome (SPS) causes you to have muscle stiffness and spasms, often triggered by sudden noises or touch. You can use medications like muscle relaxants and anticonvulsants to relieve ...

ME/CFS is a neurological condition characterized by malaise. Diagnosis requires ruling out other systemic illnesses.