Orthostatic hypotension: A temporary lowering of blood pressure, usually related to suddenly standing up. Healthy people may experience orthostatic hypotension if they rise quickly from a seated position, especially after a meal. Orthostatic hypotension occurs most commonly in older people. The change in position causes a temporary reduction in blood flow and therefore a shortage of oxygen to the brain. This leads to lightheadedness, dizziness, and, sometimes, a temporary loss of consciousness. Tilt-table testing can be used to confirm a diagnosis of 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 are measured while symptoms are recorded in various positions. Also known as postural hypotension.