Squatting for a while, stand up, giddy eyes, black eyes, what's going on?

Squatting for a while stand up dizziness, black eyes, generally considered to be caused by orthostatic hypotension. Usually pay attention to change the position when the movement should be slow, but also should monitor blood pressure changes. There may be insufficient blood supply to the brain caused by patients. Usually need to rest, drink more water, conducive to alleviate the condition.