A physician always tries to determine the cause of low blood pressure (hypotension) to determine the treatment and to ensure that it is not due to a more serious problem, such as heart disease. Underlying heart disease, such as an abnormal heart rhythm (arrhythmia) or narrowing (stenosis) of a heart valve, can be life-threatening.

Important factors considered when making a diagnosis include the patient’s age, the conditions under which the symptoms occurred and the symptoms themselves. An electrocardiogram (EKG) and an echocardiogram are noninvasive tests that are essential. Blood tests (e.g., glucose test, complete blood count and hematocrit calculation) can help rule out hypoglycemia and anemia.

A 24-hour Holter monitor or a 30-day loop recorder may be necessary to record the heart’s electrical activity for a longer period of time. These devices are used while patients go about their daily routine to detect an abnormal heart rhythm or heart block. An exercise stress test or an electrophysiology study may also be helpful.

Serious forms of neurally mediated hypotension may also require a tilt test table. This test is often used to diagnose significant hypotension-related problems and to evaluate the body's reaction to its position and position changes over time. In a tilt table test, the patient lies down on a table and is strapped to it. The table is raised to an upright position where the patient may remain for up to one hour. blood pressure, heart rate and symptoms (e.g., dizziness or faintness) will be recorded. Results will help to determine diagnosis and any further treatment. Medications may be given to the patient during the study to enhance the sensitivity of the study and to guide treatment.