Orthostasis means upright posture, and hypotension means low blood pressure. Thus, orthostatic hypotension consists of symptoms of dizziness, faintness or lightheadedness which appear only on standing, and which are caused by low blood pressure. Only rarely is spinning vertigo caused by orthostasis.

What Causes Orthostatic Hypotension?
Blood pressure is maintained by a combination of several things. The heart is the central pump, and a weak or irregular heart can cause orthostatic hypotension. Conditions such as arrhythmia, heart failure, deconditioning, and pregnancy are examples where the heart may not be up to the task of providing an adequate blood pressure.

The heart pumps blood, and if there is too little blood volume (anemia, dehydration, dialysis), the pressure drops. The blood vessels in the body also can squeeze (constrict) to raise blood pressure, and if this action is paralyzed, blood pressure may fall. Numerous medications affect blood vessels including most of the medications used for blood pressure, and many of the medications used in psychiatry and for anginal heart pain. Heat, such as a hot shower or from a fever can also dilate blood vessels and cause orthostasis. The nervous system senses and responds to regulate blood pressure. If something is wrong in this control system, blood pressure may fluctuate.

Blood pressure is usually lowered (in persons with orthostasis) by upright posture, food, infection, hyperventilation, hot weather, and lifting of heavy objects. General anesthesia may be unusually dangerous due to blood pressure fluctuations. Vestibular disorders may interact with blood pressure and heart rate control. The vestibular system is one source of information about uprightness (the otoliths), there are some effects of vestibular stimulation on the heart, and there are some patients who have a combination of autonomic and vestibular symptoms.

Non-Drug Treatment for Orthostatic Hypotension
Generally it is best to start with non-pharmacological treatment, and proceed to drug treatment only when this fails. Note that measures such as volume expansion with increased salt and fluid, moderate exercise and tilt training are relatively safe but their effectiveness has not been demonstrated by controlled trials. Nevertheless, we think it is reasonable to give these things a try.

Use an automatic blood pressure cuff. Check blood pressure and pulse daily, preferably standing and lying flat, and record it. Also check blood pressure when you have symptoms.

If possible, eliminate medications that lower blood pressure (usually blood-pressure or heart medications). Check with your doctor first, however, to be sure that this is safe. Sometimes it is helpful to take the blood pressure medications in the evening, as well as to use longer acting ones rather than ones that act quickly.

Take in extra amounts of salt - about 10 gm/day total. Another way to get extra salt is to use salt containing beverages (e.g. "gatorade"). If you start to have trouble breathing or get excessive swelling at the ankles, you may have to use less than 10 gm. Similarly, be careful not to overdo it and end up with hypertension.

Two strong cups of coffee in the morning may be helpful.

Wear Jobst stockings (tight custom made leotard like garment -- worn by both men and women). These are often not well tolerated, especially in the summer. There are also similar compression garments for sports use that cover more territory.

Sleep with head of bed elevated about 15-20 degrees (4-6 inches). This maneuver increases blood volume and, after a few days, is helpful.  It is also helpful in that it may reduce supine hypertension( sometimes blood pressure is too high lying flat, and too low standing up). Try to be up during the day, not lying in bed. Reconditioning may be helpful for persons who have been on bed rest for long periods of time.