Orthostatic hypotension

Orthostatic hypotension (also known as postural hypotension and, colloquially, as head rush or a dizzy spell) is a sudden fall in blood pressure, typically greater than 20/10 mm Hg, that occurs when a person assumes a standing position, usually after a prolonged period of rest.

Symptoms
Symptoms, which generally occur after sudden standing, include dizziness, lightheadedness, headache, blurred or dimmed vision (possibly to the point of momentary blindness), and fainting. It can be caused by blood pooling in the lower extremities; venous return and cardiac output are further compromised, resulting in further lowering of arterial pressure.

Causes
Orthostatic hypotension is significantly more common in tall patients.

It may be caused by hypovolemia (a decreased amount of blood in the body), resulting from bleeding, the excessive use of diuretics, vasodilators, or other types of drugs, dehydration, or prolonged bed rest.

It also occurs in people with anemia.

Short lived episodes of orthostatic hypotension are common in children.

It can be a side effect of certain anti-depressants, such as tricyclics or MAOIs.

The disorder may be associated with Addison's disease, atherosclerosis (build-up of fatty deposits in the arteries), diabetes, pheochromocytoma, and certain neurological disorders including Shy-Drager syndrome and other forms of dysautonomia.

Treatment and management
When orthostatic hypotension is caused by hypovolemia due to medications, the disorder may be reversed by adjusting the dosage or by discontinuing the medication. When the condition is caused by prolonged bed rest, improvement may occur by sitting up with increasing frequency each day. In some cases, physical counterpressure such as elastic hose or whole-body inflatable suits may be required. Dehydration is treated with salt and fluids.

The prognosis for individuals with orthostatic hypotension depends on the underlying cause of the condition.

Medical management
Some drugs that are used in the treatment of orthostatic hypotension include fludrocortisone (Florinef), erythropoietin and midodrine. Pyridostigmine bromide (Mestinon) is now also used to treat orthostatic hypotension.

Lifestyle advice
Some suggestions for minimizing the effects include:


 * Checking blood pressure regularly with a home monitoring kit. Check when lying flat and when standing as well as when symptoms occur.
 * Standing slowly rather than quickly, as the delay can give the blood vessels more time to constrict properly. This can help avoid incidents of syncope.
 * Take a deep breath and flex your abdominal muscles while rising to maintain blood and oxygen in the brain (may be contraindicated in individuals with Stage 3 hypertension).
 * Maintaining an elevated salt intake, through sodium supplements or electrolyte-enriched drinks. A suggested value is 10 g per day; overuse can lead to hypertension and should be avoided.
 * Maintaining a proper fluid intake to prevent the effects of dehydration.
 * As eating lowers blood pressure, eat multiple smaller meals rather than fewer larger meals. Take extra care when standing after eating.