Signs and Symptoms - Head Rushes
Many people experience dizziness, faintness or light-headedness when they stand up. This is called postural hypotension (low blood pressure), and is due to a drop in blood pressure when going from a sitting to a stanging position. Usually, this is not a problem, as long as it occurs occasionally, and is often treated with the simple advice of "get up more slowly". Dehydration can increase this effect because of the limited amounts of fluid in the body so special precautions should be taken when changing from horizontal to vertical.