Presyncope

Presyncope is a state consisting of lightheadedness, muscular weakness, and feeling faint (as opposed to a syncope, which is actually fainting). Pre-syncope is most often cardiovascular in etiology. In many patients, lightheadedness is a symptom of orthostatic hypotension. Orthostatic hypotension occurs when blood pressure drops significantly when the patient stands from a supine or sitting position. If loss of consciousness occurs in this situation, it is termed syncope.

Presyncope is frequently reported in patients with forms of Dysautonomia such as the Postural Tachycardia Syndrome.

According to McGraw-Hill Concise Dictionary of Modern Medicine &copy; 2002, presyncope is "An episode of near-fainting which may include lightheadedness, dizziness, severe weakness, blurred vision, which may precede a syncopal episode."

Clinical test
The tilt table test is an evaluative clinical test to help identify presyncope or syncope. A tilt angle of 60 and 70 degrees is optimal and maintains a high degree of specificity. A positive sign with the tilt table test must be taken in context of patient history, with consideration of pertinent clinical findings before coming to a conclusion.