Hypotension, orthostatic: A temporary lowering of blood pressure (hypotension) due usually to suddenly standing up (orthostatic). Orthostatic hypotension may be experienced by healthy people -- it is more common in older people -- who rise quickly from a chair, especially after a meal, and have a few seconds of disorientation.
The change in position causes a temporary reduction in blood flow and therefore a shortage of oxygen to the brain. This leads to lightheadedness and, sometimes, a "black out" episode, a loss of consciousness.
Symptoms include dizziness, feeling about to black out, and tunnel vision (all due to insufficient bloodflow to the brain). The symptoms are typically worse when standing and improve with lying down.
Tilt-table testing can be used to confirm orthostatic hypotension. Tilt-table testing involves placing the patient on a table with a foot-support. The table is tilted upward and blood pressure and pulse is measured while symptoms are recorded in various positions.
No treatment is needed for orthostatic hypotension. If someone with orthostatic hypotension faints, they will regain consciousness by simply sitting or lying down.
The person is thereafter advised to exercise caution and slow the process of changing positions from lying to sitting to standing. This simple technique can allow the body to correct for the more a vertical position by a gradual adjustment of the circulation of the legs. It can be especially important for older people.
Orthostatic hypotension is also called postural hypotension.