Blood pressure (BP) is the pressure with which out heart pumps blood to the various organs of the body. The normal pressure of this activity is 120/180 mmHg. Any figure below or above this is considered unhealthy and even fatal for the person experiencing it. A person experiencing dizziness or persistent headaches for several days altogether that makes him/ her feel nauseous is sign of rising BP associated with hypertension. While high pressure in blood is extremely dangerous and should be immediately restored to normal, what causes high pressure in blood is the question that must be taken into account so as to avoid encountering this problem.