Orthostatic Hypotension
Orthostatic hypotension is a sudden fall in blood pressure that occurs when a person assumes a standing position. It is due to a lesion of the baroreflex loop, which senses a change in blood pressure and adjusts heart rate and activates sympathetic nerve system fibers to cause the blood vessels to narrow and correct blood pressure. It may also be caused by hypovolemia (a decreased amount of blood in the body), resulting from the excessive use of diuretics, vasodilators, or other types of drugs, dehydration, or prolonged bed rest. The disorder may be associated with Addison's disease, diabetes, and certain neurological disorders including Multiple System Atrophy with Orthostatic Hypotension (formerly known as Shy-Drager syndrome), autonomic system neuropathies, and other dysautonomias. Symptoms, which generally occur after sudden standing, include dizziness, lightheadedness, blurred vision, and syncope (temporary loss of consciousness).
Treatment
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. More severe cases can be treated with drugs, such as midodrine, to raise blood pressure.
Prognosis
The prognosis for individuals with orthostatic hypotension depends on the underlying cause of the condition.
Research
The NINDS supports research on conditions such as neurogenic orthostatic hypotension aimed at increasing scientific understanding of the condition and finding ways to treat and prevent it.
Organizations
National Organization for Rare Disorders (NORD)
Federation of voluntary health organizations dedicated to helping people with rare "orphan" diseases and assisting the organizations that serve them. Committed to the identification, treatment, and cure of rare disorders through programs of education, advocacy, research, and service.
55 Kenosia Avenue
Danbury, CT 06810
orphan@rarediseases.org
http://www.rarediseases.org
Tel: Danbury
Fax: 203-798-2291
National Heart, Lung, and Blood Institute (NHLBI)
National Institutes of Health, DHHS
31 Center Drive, Rm. 4A21 MSC 2480
Bethesda, MD 20892-2480
http://www.nhlbi.nih.gov
Tel: Bethesda
Content Provided By
NINDS Disorders is an index of neurological conditions provided by the National Institute of Neurological Disorders and Stroke. This valuable tool offers detailed descriptions, facts on treatment and prognosis, and patient organization contact information for over 500 identified neurological disorders.
