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Postural orthostatic tachycardia syndrome (POTS) is one of a group of disorders that have orthostatic intolerance (OI) as their primary symptom.OI describes a condition in which an excessively reduced volume of blood returns to the heart after an individual stands up from a lying down position.n POTS, the lightheadedness or fainting is also accompanied by a rapid increase in heartbeat of more than 30 beats per minute, or a heart rate that exceeds 120 beats per minute, within 10 minutes of rising. The faintness or lightheadedness of POTS are relieved by lying down again.
Postural tachycardia syndrome is an abnormality of the functioning of the autonomic (involuntary) nervous system. To be diagnosed with PoTS, an individual must experience a group of symptoms in the upright position (usually standing) that are relieved by lying down.A persistent increase in heart rate of 30 beats per minute (40 bpm if under 19 years of age) should be recorded within ten minutes of standing.he Postural Tachycardia Syndrome (PoTS) is an abnormality of the autonomic nervous system (sometimes called âdysautonomiaâ). The autonomic nervous system (ANS) is in charge of all bodily functions that we donât have to think about, such as: 1  Heart rate and blood pressure regulation. 2  Digestion. 3  Bladder control. 4  Sweating.