A tilt table test is used to evaluate the cause of unexplained fainting or severe lightheadedness. During the test, your blood pressure and heart rate are monitored. You begin by lying flat on a table. The table is then tilted to raise the upper part of your body— simulating a change in position from lying down to standing up. This test allows doctors to evaluate your body’s cardiovascular response to this change in position. When you stand up, gravity causes blood to pool in your leg veins, reducing the amount of blood that returns to your heart. This can cause your blood pressure to decrease (orthostatic hypotension). Normally, one’s body quickly compensates but if these mechanisms do not work normally, the drop in blood pressure can be severe enough to cause fainting.