Blood pressure

Blood pressure (BP) is a term in physiology for the pressure of the blood against the inner wall of the blood vessels in the circulatory system of the body. It is often measured for diagnosis purposes. It varies in different parts of the body under different conditions of exertion and health. It is closely related to the heartbeat and relative to the elasticity and diameter of the vessels and the rate and force of the heartbeat. Blood pressure is measured in numbers, the upper number is called systolic, and lower number is called diastolic, such as 120/80 mm Hg. A BP less than 120/80 mm Hg but not below 90/60 millimetre of Mercury is considered normal in human beings. A blood pressure lower than 90 mm Hg for systolic or 60 mm Hg for diastolic is called low blood pressure or hypotension. If the systolic ranges between 120-129 but the diastolic remain less than 80, we call it elevated blood pressure. High blood pressure or hypertension Stage I has a range 130-139, or 80-89; Stage II has 140 and above, or 90 and above; and hypersensitivity crisis has 180 and above and/or 120 and above for higher and lower sides respectively.