Orthostatic Hypotension - Causes, Signs and Symptoms
Orthostatic hypotension is a drop in blood pressure that occurs suddenly when changing position from supine to sitting or upright position. Orthostatic hypotension is more frequent in patients taking antihypertensive medications. Symptoms such as sudden weak, dizzy, felt faint and fainting may occur. Orthostatic hypotension is often mild, lasting a few seconds to several minutes after standing. However, prolonged orthostatic hypotension may be a sign of a more serious problem, so it needs to consult with a doctor if they occur. Moreover, in case of loss of consciousness although momentarily. Mild orthostatic hypotension often do not require treatment. Many people sometimes feel dizzy or lightheaded after standing, and usually do not cause concern. Treatment for more severe cases of orthostatic hypotension depends on the cause. Orthostatic hypotension was defined as a decrease in systolic blood pressure of 20 mmHg or diastolic blood pressure 10 mmHg within three minutes of standing compared with blood pressure from sitting or supine position.
Orthostatic hypotension is caused primarily by gravity-induced blood-pooling in the lower extremities, which in turn compromises venous return, resulting in decreased cardiac output and subsequent lowering of arterial pressure. For example, changing from a lying position to standing loses about 700 ml of blood from the thorax, with a decrease in systolic and diastolic blood pressures. The overall effect is an insufficient blood perfusion in the upper part of the body.
Still, the blood pressure does not normally fall very much, because it immediately triggers a vasoconstriction (baroreceptor reflex), pressing the blood up into the body again. (Often, this mechanism is exaggerated and is why diastolic blood pressure is a bit higher when a person is standing up, compared to a person in horizontal position.) Therefore, a secondary factor that causes a greater than normal fall in blood pressure is often required. Such factors include hypovolemia, diseases, and medications.
Signs and symptoms
When orthostatic hypotension is present, the following symptoms can occur after sudden standing or stretching (after standing):
- Dizziness
- Euphoria or dysphoria
- Bodily dissociation
- Distortions in hearing
- Lightheadedness
- Nausea
- Headaches
- Temporary decrease in hearing
- Blurred or dimmed vision (possibly to the point of momentary blindness)
- Seizures
- Generalized (or extremity) numbness/tingling and fainting
- Coat hanger pain (pain centered in the neck and shoulders)
- And in rare, extreme cases, vasovagal syncope (a specific type of fainting).
