Haitham Ahmad Abdulrazzeq
Postural Orthostatic Tachycardia Syndrome is a Disorder of the Autonomic Nerviuos System. When a normal Person, stand up from sitting position , pooling down of blood occurs as a result of Gravity drop of the blood flow to the brain occur as well . As a compensatory mechanism, the body reacts by peripheral vaso-constriction and increase in the heart rate , in order to maintain sufficient blood flow to the brain. That occurs by activation of the Normal Autonomic Nervious System.