Presyncope is a state consisting of lightheadedness, muscular weakness, blurred vision, and feeling faint (as opposed to a syncope, which is actually fainting). Presyncope 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.