Orthostatic hypotension is a condition of abnormal blood pressure regulation upon standing. The blood pressure dramatically decreases (more than 20/10 mm Hg) when rising from a lying down or sitting position to a standing position.
Causes
Orthostatic hypotension has several causes.
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Hypovolemia is the most common cause. It may be due to:
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Impaired autonomic (nerve) reflex due to certain diseases:
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Decreased heart muscle contractility or vascular responsiveness
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Certain drugs:
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Tricyclic antidepressants (nortriptyline, amitriptyline, desipramine, imipramine, protriptyline)
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Phenothiazine antipsychotic drugs (chlorpromazine, promazine, thioridazine)
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Quinidine
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Levodopa
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Barbiturates
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Alcohol
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors include:
Symptoms
Symptoms include:
Exercise or having eaten a heavy meal may worsen symptoms.
If you experience any of these symptoms do not assume it is due to orthostatic hypotension. These symptoms may be caused by other health conditions. If you experience any one of them, see your doctor.
Diagnosis
Orthostatic hypotension is diagnosed when symptoms are present and there is a measured reduction in blood pressure while standing, which is relieved by lying down. The underlying cause must be determined on an individual basis.
Treatment
Treatment for orthostatic hypotension depends on the cause.
Treatments include:
Adjusting Dosage or Type of Medication
When orthostatic hypotension is due to hypovolemia related to medications, an adjustment in the dosage or discontinuing the medication may be needed to reverse the condition.
Treating Dehydration
Orthostatic hypotension resulting from dehydration is treated with fluids and electrolyte (mainly sodium) replacement.
Minimizing Bed Rest
If bed rest is the cause of orthostatic hypotension, symptoms of orthostatic hypotension may be improved by increasing time spent sitting up in bed.
Medications
A number of medications may be given to boost blood pressure, including:
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Fludrocortisone
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Pindolol
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Dihydroergotamine
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Ibuprofen
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Clonidine
Other Interventions
In some cases, individuals may be encouraged to increase their intake of salt. Fitted elastic stockings that go up to the waist may be worn. Individuals may need to be taught to rise from lying down, to sit up, and to stand in a slow and gradual fashion. Similarly, they should be discouraged from standing still for too long a time.
Prevention
There is no way to prevent orthostatic hypotension if it is a result of other diseases or conditions. However, if your orthostatic hypotension relates to medications, dehydration, or bed rest, you should talk with your healthcare provider about adjusting your medications, drinking adequate fluids, and minimizing bed rest, respectively.
RESOURCES:
National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov
National Organization for Rare Disorders
http://www.rarediseases.org
References:
Beers MH et al. The Merck Manual of Medical Information—Home Edition, 2nd ed. Simon and Schuster, Inc.; 2003.
Ferri FF. Ferri's Clinical Advisor: Instant Diagnosis and Treatment, 8th ed., St. Louis: Mosby; 2006.
Goldman L. Cecil Textbook of Medicine, 22nd ed. Philadelphia: Saunders; 2004.
Lenders JW, Eisenhofer G, Mannelli M, et al. Phaeochromocytoma. Lancet. 2005 Aug 20-26;366(9486):665-75.
The Merck Manual of Diagnosis and Therapy website. Available at:http://www.merck.com.
National Institute of Neurological Disorders and Stroke website. Available at:http://www.ninds.nih.gov.
