Types of Hypotension

There are several types of hypotension. One type, chronic asymptomatic hypotension, happens in people who always have low blood pressure. They have no symptoms and need no treatment. Their low blood pressure is normal for them.

Other types of hypotension happen only sometimes, when blood pressure suddenly drops too low. The symptoms and effects on the body can be mild or severe. The three main types of this kind of hypotension are orthostatic hypotension, neurally mediated hypotension (NMH), and severe hypotension associated with shock.

Orthostatic Hypotension

Orthostatic hypotension is low blood pressure that occurs upon standing up from a sitting or lying down position. It can cause a person to feel dizzy, lightheaded or even to faint. It occurs when the body is not able to adjust blood pressure and blood flow fast enough for the change in position. Usually orthostatic hypotension lasts for only a few seconds or minutes after a person stands up. Sometimes a person will need to sit or lie down for a short time while the blood pressure returns to normal.

Orthostatic hypotension can occur in all age groups, but it is more common in older adults, especially those who are frail or in poor health. Orthostatic hypotension can be a symptom of other medical conditions, and treatment generally focuses on treating the underlying condition(s). Some people can have orthostatic hypotension but also have high blood pressure when lying down.

A form of orthostatic hypotension called postprandial hypotension is a sudden drop in blood pressure after a meal. Postprandial hypotension most commonly affects older adults. It also is more likely to affect those with high blood pressure or diseases such as Parkinson disease.

Neurally Mediated Hypotension

In this form of hypotension, blood pressure drops after a person has been standing for a long time. A person may feel dizzy, faint, or sick to the stomach as a result. NMH also can happen when a person faces an unpleasant, upsetting, or frightening situation.

NMH affects children and young adults more often than other age groups. Children often outgrow this form of hypotension.

Severe Hypotension Associated With Shock

Many times people will say a person has "gone into shock" as a result of an emotionally upsetting experience. But to doctors, the word "shock" has a different meaning. Shock is a life-threatening condition in which blood pressure drops so low that the brain, kidneys, and other vital organs can't get enough blood to work properly. It is different from the other forms of hypotension because blood pressure drops much lower, and it is life threatening if not treated immediately. There are many causes of shock, including major loss of blood, certain severe types of infection, severe burns, severe allergic reactions, and poisoning.