Gender differences in orthostatic hypotension.

Orthostatic hypotension is a decrease in systolic blood pressure of more than 20 mm Hg or a decrease in diastolic blood pressure of at least 10 mm Hg, within 3 minutes of changing from a supine to an upright position. The typical clinical presentation of orthostatic hypotension includes dizziness, syncope, blurry vision and loss of balance. Symptoms may be more frequent in women, but the complicating roles played by comorbid factors and the estrogen mechanisms are not well understood. Women have a more active parasympathetic system, higher estrogen levels and a lower center of gravity. Thus, women less effectively compensate for the drop of blood pressure in response to positional change. An understanding of these mechanisms contributing to orthostatic hypotension may improve diagnosis and treatment of the problem.