Your doctor's goal in evaluating orthostatic hypotension is to find the underlying cause, and determine appropriate treatment for any health problems that may cause your low blood pressure. The cause isn't always known.
Your doctor may review your medical history, review your symptoms and conduct a physical examination to help diagnose your condition.
Your doctor also may recommend one or more of the following:
- Blood pressure monitoring. Your doctor will measure your blood pressure both while you're sitting and while you're standing and will compare the measurements. Your doctor will diagnose orthostatic hypotension if you have a drop of 20 millimeters of mercury (mm Hg) in your systolic blood pressure or a drop of 10 mm Hg in your diastolic blood pressure within two to five minutes of standing up, or if standing causes signs and symptoms.
- Blood tests. These can provide information about your overall health, including low blood sugar (hypoglycemia) or low red blood cell levels (anemia), both of which can cause low blood pressure.
Electrocardiogram (ECG or EKG). This noninvasive test detects irregularities in your heart rhythm or heart structure, and problems with the supply of blood and oxygen to your heart muscle.
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.
Sometimes, heart rhythm abnormalities come and go, and an ECG won't find any problems. If this happens, you may be asked to wear a 24-hour Holter monitor to record your heart's electrical activity as you go about your daily routine.
Echocardiogram. In this noninvasive exam, sound waves are used to produce a video image of your heart. Sound waves are directed at your heart from a wandlike device (transducer) that's held on your chest.
The sound waves that bounce off your heart are reflected through your chest wall and processed electronically to provide video images of your heart in motion to detect underlying structural heart disease.
- Stress test. A stress test is performed while you're exercising, such as walking on a treadmill. Or you may be given medication to make your heart work harder if you're unable to exercise. When your heart is working harder, your heart will be monitored with electrocardiography, echocardiography or other tests.
- Tilt table test. A tilt table test evaluates how your body reacts to changes in position. You'll lie on a flat table that tilts to raise the upper part of your body, which simulates the movement from a horizontal to standing position. Your blood pressure is taken frequently as the table is tilted.
- Valsalva maneuver. This noninvasive test checks the functioning of your autonomic nervous system by analyzing your heart rate and blood pressure after several cycles of a type of deep breathing: You breathe in deeply and push the air out through your lips, as if you were trying to blow up a stiff balloon.