Squatting stand up giddy before blackened faint, how to return a responsibility

Squatting stand up dizziness before the black fainted phenomenon, usually considered to be caused by orthostatic hypotension. Because the patient squatted for a long time, leading to the body's blood circulation is not smooth. Thus causing blood stasis in the lower limbs, a long time after suddenly standing will cause the body to appear brain hypoxia phenomenon and cause dizziness.