Postural orthostatic tachycardia syndrome

Postural orthostatic tachycardia syndrome (POTS, also known as postural tachycardia syndrome) is a condition in which a change from the supine position to an upright position causes an abnormally large increase in heart rate, called tachycardia. Other symptoms of an orthostatic nature — occurring in response to upright posture — may accompany the tachycardia.