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Low Blood Pressure

Picture: A woman feeling light-headed and dizzy as a result of low blood pressure.
Low Blood Pressure

Low Blood Pressure
(Hypotension)

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Low Blood Pressure and Stress

Can Stress Contribute to Low Blood Pressure?

Viewer Question: I've heard that stress may cause high blood pressure, but can it also cause low blood pressure?

Doctor's Answer: Low blood pressure is hard to define, because a lowered blood pressure can occur naturally in persons who exercise regularly, keep a normal weight, and eat a healthy diet. Many experts use the arbitrary criteria of a systolic (top) pressure of 90 or lower or a diastolic (bottom) pressure of 60 or less to be the cutoff levels used to define low blood pressure. But in some cases, low blood pressure accompanies certain medical conditions and may be a sign of life-threatening illness.

What is low blood pressure?

Blood pressure is the force exerted by circulating blood on the walls of blood vessels. It constitutes one of the critically important signs of life or vital signs which include heart beat, breathing, and temperature. Blood pressure is generated by the heart pumping blood into the arteries modified by the response of the arteries to the flow of blood.

An individual's blood pressure is expressed as systolic/diastolic blood pressure, for example, 120/80.The systolic blood pressure (the top number) represents the pressure in the arteries as the muscle of the heart contracts and pumps blood into them. The diastolic blood pressure (the bottom number) represents the pressure in the arteries as the muscle of the heart relaxes following its contraction. Blood pressure always is higher when the heart is pumping (squeezing) than when it is relaxing.

The range of systolic blood pressure for most healthy adults falls between 90 and 120 millimeters of mercury (mm Hg). Normal diastolic blood pressure ranges between 60 and 80 mm Hg. Current guidelines define normal blood pressure range as lower than 120/80. Blood pressures over 130/80 are considered high. High blood pressure increases the risk of developing:

Low blood pressure (hypotension) is pressure so low it causes symptoms or signs due to the low flow of blood through the arteries and veins. When the flow of blood is too low to deliver enough oxygen and nutrients to vital organs such as the brain, heart, and kidney, the organs do not function normally and may be temporarily or permanently damaged.

Unlike high blood pressure, low blood pressure is defined primarily by signs and symptoms of low blood flow and not by a specific blood pressure number. Some individuals routinely may have blood pressures of 90/50 with no symptoms and therefore do not have low blood pressure. However, others who normally have higher blood pressures may develop symptoms of low blood pressure if their blood pressure drops to 100/60.



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Low Blood Pressure - Causes Question: What caused your blood pressure to be abnormally low?