Blood pressure is caused by the force of the blood as it pushes against artery walls, according to WebMD. This pressure is measured during the active and resting phases of every heartbeat.
Low blood pressure, or hypotension, occurs when a person's blood pressure measures below 90 for systolic and 60 for diastolic, according to WebMD. Having just one number below these given figures is enough for a person to have hypotension.
According to About.com, normal blood pressure is 120 millimeters of mercury during a heart contraction and 80 millimeters of mercury during relaxation. This results in blood pressure readings in the range of 120/70 to 140/90. Blood pressure readings that surpass that am...
A blood pressure reading below 120/80 mm Hg is a good blood pressure reading, according to the National Heart, Lung, and Blood Institute. Low readings are usually best, but the American Heart Association warns that low blood pressure can cause unpleasant side effects, s...
According to Mayo Clinic, primary hypertension, or high blood pressure, has no identifiable causes and develops over time. Medical conditions such as chronic kidney disease, thyroid disease, sleep apnea, congenital blood defects and adrenal gland tumors are causes of se...
Blood pressure represents the pressure of blood in the arteries as the heart contracts and when it is at rest, according to WebMD. The pressure in the arteries right after the heart contracts is called systolic blood pressure, and the pressure when the heart rests is ca...
Blood pressure affects the vital organs and the health of the arteries, as reported by the American Heart Association. Someone with consistently elevated blood pressure has an increased risk for arterial damage, blood clots and organ damage.