Postural orthostatic hypotension syndrome, also known as POTs, is a disorder where the heart rate increases significantly in patients when they assume the upright position within a ten minute period of time and can cause a constellation of symptoms. The symptoms are part of a spectrum of orthostatic intolerance (OI).
Before understanding exactly what POTs is, one needs to understand the symptoms of orthostatic intolerance. Orthostatic intolerance is the development of symptoms which occurs when an individual stands upright from a lying or sitting position. These symptoms are relieved when the patient reclines. When orthostatic intolerance can occur in an acute setting when patients are dehydrated or have taken medications that can lower blood pressures when they stand up, these are termed secondary orthostatic intolerance. Primary orthostatic intolerance occurs in the absence of dehydration or medications causing the abrupt symptoms that occur when an individual assumes the upright position.