Clinical Definition

Low blood pressure, or hypotension, occurs when the pressure of the blood in your arteries is much lower than normal, leading to an inadequate blood supply for the heart, brain and other body parts. Normally, a healthy blood pressure goal is less than 120/80; low pressure is typically below 90/60. Causes of severe hypotension are varied; if a low pressure does not cause problems, it does not need treatment.

In Our Own Words

Low blood pressure, or hypotension, is a problem when it qualifies as “below spec” in terms of what the body needs. This results in preventing the heart, brain and other organs from getting enough blood. A pressure less than 120/80 is the goal for healthy pressure. However, when these numbers fall below 90/60, this is usually defined as low blood pressure because we can begin to see related problems. In general, lower pressures that cause no problems need no treatment; other scenarios are treated case-by-case.

Severe hypotension could be the result of a sudden loss of blood, severe infection, heart attack, a severe allergic reaction, medicines and other causes. Orthostatic hypotension, perhaps the most common kind of hypotension, has many causes and is characterized by a drop in blood pressure from a sudden change in posture (usually when someone stands suddenly) and is associated with dehydration, pregnancy (i.e., venous pooling), anemia and medications. Neurally mediated hypotension (NMH) is another type, affecting young adults and children most often after they have been standing for long periods of time. However, neurally mediated hypotension can typically be outgrown.