Diagnosis

The goal in testing for low blood pressure is to find the cause. Besides taking your medical history, doing a physical exam and measuring your blood pressure, your doctor might recommend the following:

• Blood tests. These can provide information about your overall health as well as whether you have low blood sugar (hypoglycemia), high blood sugar (hyperglycemia or diabetes) or a low red blood cell count (anemia), all of which can cause lower than normal blood pressure.

• Electrocardiogram (ECG). During this painless, noninvasive test, soft, sticky patches (electrodes) are attached to the skin of your chest, arms and legs. The patches detect your heart's electrical signals while a machine records them on graph paper or displays them on a screen.

  An ECG, which can be performed in your doctor's office, detects irregularities in your heart rhythm, structural problems in your heart, and problems with the supply of blood and oxygen to your heart muscle. It can also tell if you're having a heart attack or have had one in the past.

• Tilt table test. If you have low blood pressure on standing or from faulty brain signals (neurally mediated hypotension), a tilt table test can evaluate how your body reacts to changes in position.

  During the test, you lie on a table that's tilted to raise the upper part of your body, which simulates the movement from horizontal to a standing position.