The problem, a brief but precipitous drop in blood pressure that causes lightheadedness or dizziness when standing up, is called orthostatic hypotension.
Orthostatic hypotension — to many people those are unfamiliar words for a relatively common but often unrecognized medical problem that can have devastating consequences, especially for older adults. It refers to a brief but precipitous drop in blood pressure that causes lightheadedness or dizziness when standing up after lying down or sitting, and sometimes even after standing, for a prolonged period.
The problem is likely to be familiar to people of all ages who may have been confined to bed for a long time by an injury, illness or surgery. It also often occurs during pregnancy. But middle-aged and older adults are most frequently affected.
A significant number of falls and fractures, particularly among the elderly, are likely to result from orthostatic hypotension — literally, low blood pressure upon standing. Many an older person has fallen and broken a hip when getting out of bed in the morning or during the night to use the bathroom, precipitating a decline in health and loss of independence as a result of this blood pressure failure.
Orthostatic hypotension is also a risk factor for strokes and heart attacks and even motor vehicle accidents. It can be an early warning sign of a serious underlying cardiovascular or neurological disorder, like a heart valve problem, the course of which might be altered if detected soon enough. But as one team of specialists noted, although orthostatic hypotension is a “highly prevalent” disorder, it is “frequently unrecognized until late in the clinical course.”
Under normal circumstances, when we stand up, gravity temporarily causes blood to pool in the lower half of the body; then, within 20 or 30 seconds, receptors in the heart and carotid arteries in the neck trigger a compensating mechanism called the baroreflex that raises the heart rate and constricts blood vessels to increase blood pressure and provide the brain with an adequate supply of blood.
In people with orthostatic hypotension, this reflex mechanism is delayed or insufficient, resulting in such symptoms as lightheadedness, dizziness, palpitations, blurred vision, weakness, confusion or fainting.