There are several types of hypotension. People who always have low blood pressure have chronic asymptomatic hypotension. They have no signs or symptoms and need no treatment. Their low blood pressure is normal for them.
Other types of hypotension occur only sometimes, when blood pressure suddenly drops too low. The symptoms and effects on the body range from mild to severe.
The three main types of this kind of hypotension are orthostatic (OR-tho-STAT-ik) hypotension, neurally mediated hypotension (NMH), and severe hypotension linked to shock.
This type of low blood pressure occurs when standing up from a sitting or lying down position. It can make you feel dizzy or lightheaded, or even make you faint.
Orthostatic hypotension occurs if your body isn't able to adjust blood pressure and blood flow fast enough for the change in position. This type of low blood pressure usually lasts for only a few seconds or minutes after you stand up. You may need to sit or lie down for a short time while your blood pressure returns to normal.
Orthostatic hypotension can occur in all age groups. However, it's more common in older adults, especially those who are frail or in poor health. It can be a symptom of other medical conditions, and treatment often focuses on treating the underlying condition(s).
Some people 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. This type of low blood pressure mostly affects older adults. It’s also more likely to affect people who have high blood pressure or a central nervous system disorder, such as Parkinson’s disease.
Neurally Mediated Hypotension
With NMH, blood pressure drops after you've been standing for a long time. You may feel dizzy, faint, or sick to the stomach as a result. This type of low blood pressure also can occur if you have an unpleasant, upsetting, or scary experience.
NMH affects children and young adults more often than people in other age groups. Children often outgrow NMH.
Severe Hypotension Linked to Shock
People may say a person has “gone into shock” as a result of an upsetting event. 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. Blood pressure drops much lower in shock than in other types of hypotension.
Many factors can cause shock, such as major blood loss, certain severe infections, severe burns and allergic reactions, and poisoning. Shock can be fatal if it's not treated right away.