digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

"Head rush" redirects here. For the television science series, see Head Rush (TV series).
Orthostatic hypotension
Classification and external resources
ICD-10 I95.1
ICD-9 458.0
DiseasesDB 10470
eMedicine ped/2860
MeSH D007024

Orthostatic hypotension (/ˌɔrθəˈstætɪkˌhpəˈtɛnʃən/), also known as postural hypotension,[1] orthostasis, and colloquially as head rush or dizzy spell, is a form of low blood pressure in which a person's blood pressure falls when suddenly standing up or stretching. In medical terms, it is defined as a fall in systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg when a person assumes a standing position.

The symptom is caused by blood pooling in the lower extremities upon a change in body position. It is quite common and can occur briefly in anyone, although it is prevalent in particular among the elderly, and those with low blood pressure.

Signs and symptoms[edit]

When orthostatic hypotension is present, the following symptoms can occur after sudden standing or stretching (after sitting):

They are consequences of insufficient blood pressure and cerebral perfusion (blood supply). Occasionally, there may be a feeling of warmth in the head and shoulders for a few seconds after the dizziness subsides. The drop in blood pressure may cause a vasovagal episode to occur.

Causes[edit]

Orthostatic hypotension is caused primarily by gravity-induced blood-pooling in the lower extremities, which in turn compromises venous return, resulting in decreased cardiac output and subsequent lowering of arterial pressure. For example, changing from a lying position to standing loses about 700 ml of blood from the thorax, with a decrease in systolic and diastolic blood pressures.[2] The overall effect is an insufficient blood perfusion in the upper part of the body.

Still, the blood pressure does not normally fall very much, because it immediately triggers a vasoconstriction (baroreceptor reflex), pressing the blood up into the body again. (Often, this mechanism is exaggerated and is why diastolic blood pressure is a bit higher when a person is standing up, compared to a person in horizontal position.) Therefore, a secondary factor that causes a greater than normal fall in blood pressure is often required. Such factors include low blood volume, diseases, and medications.

Hypovolemia[edit]

Orthostatic hypotension may be caused by low blood volume, 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.

Diseases[edit]

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 multiple system atrophy and other forms of dysautonomia. It is also associated with Ehlers-Danlos syndrome. It is also present in many patients with Parkinson's disease resulting from sympathetic denervation of the heart or as a side-effect of dopaminomimetic therapy. This rarely leads to fainting unless the person has developed true autonomic failure or has an unrelated heart problem.

Another disease, dopamine beta hydroxylase deficiency, also thought to be underdiagnosed, causes loss of sympathetic noradrenergic function and is characterized by a low or extremely low levels of norepinephrine, but an excess of dopamine.[3]

Quadriplegics and paraplegics also might experience these symptoms due to multiple systems' inability to maintain a normal blood pressure and blood flow to the upper part of the body.

A study by a Harvard Medical School team found the two sacs in the inner ear, the utricle and the saccule, affect brain blood flow; thus, inner ear problems, which increase with old age, may be involved in orthostatic hypotension.[4]

Medication[edit]

Orthostatic hypotension can be a side-effect of certain antidepressants, such as tricyclics[5] or monoamine oxidase inhibitors (MAOIs).[6] Marijuana and tetrahydrocannabinol can on occasion produce marked orthostatic hypotension.[7] Orthostatic hypotension can also be a side effect of Alpha-1 blockers (alpha1 adrenergic blocking agents). Alpha1 blockers inhibit vasoconstriction normally initiated by the baroreceptor reflex upon postural change and the subsequent drop in pressure.[8]

B12 deficiency[edit]

Orthostatic hypotension sometimes is a reversible neurological complication of vitamin B12 deficiency.[9]

Harnesses[edit]

The use of a safety harness does not contribute to orthostatic hypotension in the event of a fall. This notion is a hypothetical risk which has all but been eliminated due to modern design and safety regulations.[10] If worn properly, a safety harness may safely rescue its user from a fall without any further complications so long as the individual does not remain suspended for prolonged periods of time.[10]

Other factors[edit]

Patients prone to orthostatic hypotension are the elderly, post partum mothers, and those having been on bedrest. People suffering from anorexia nervosa and bulimia nervosa often suffer from orthostatic hypotension as a common side-effect. Consuming alcohol may also lead to orthostatic hypotension due to its dehydrating effects.[citation needed]

Diagnosis[edit]

There is a simple test for OH that measures the person's blood pressure after lying flat for 5 minutes, then 1 minute after standing, and 3 minutes after standing.[11] Orthostatic hypotension is defined as a fall in systolic blood pressure of at least 20 mmHg and/or in the diastolic blood pressure of at least 10 mmHg between the supine reading and the upright reading. In addition, the heart rate should also be measured for both positions. A significant increase in heart rate from supine to standing may indicate a compensatory effort by the heart to maintain cardiac output or Postural Orthostatic Tachycardia Syndrome (POTS). A tilt table test may also be performed.

Management[edit]

The evidence to support treatment is poor. A number of measures have slight evidence to support their use including compression bandages, midodrine, indomethacin, oxilofrine, potassium chloride, and yohimbine.[12] Midodrine can reduce dizzy spells and faints by about a third, although the quality of the evidence underlying this finding is limited.[13] The main side-effect is piloerection ("goose bumps").[13]

Prognosis[edit]

Orthostatic hypotension may cause accidental falls.[14]

See also[edit]

References[edit]

  1. ^ "Orthostatic hypotension" at Dorland's Medical Dictionary
  2. ^ http://emedicine.medscape.com/article/1154266-overview
  3. ^ "Dopamine Beta-Hydroxylase Deficiency". GeneReviews — NCBI Bookshelf. 
  4. ^ "Minute organs in the ear can alter brain blood flow". BBC News. 2009-12-27. Retrieved 2009-12-27. 
  5. ^ Jiang W, Davidson JR. (2005). "Antidepressant therapy in patients with ischemic heart disease". Am Heart J 150 (5): 871–81. doi:10.1016/j.ahj.2005.01.041. PMID 16290952. 
  6. ^ Delini-Stula A, Baier D, Kohnen R, Laux G, Philipp M, Scholz HJ. (1999). "Undesirable blood pressure changes under naturalistic treatment with moclobemide, a reversible MAO-A inhibitor—results of the drug utilization observation studies". Pharmacopsychiatry 32 (2): 61–7. doi:10.1055/s-2007-979193. PMID 10333164. 
  7. ^ Jones RT. (2002). "Cardiovascular system effects of marijuana". J Clin Pharmacol 42 (11 Suppl): 58S–63S. doi:10.1002/j.1552-4604.2002.tb06004.x. PMID 12412837. 
  8. ^ Orthostatic Hypotension at Merck Manual of Diagnosis and Therapy Home Edition
  9. ^ Beitzkea, Markus; Peter Pfistera; Jürgen Fortinb; Falko Skrabal (2002-04-18). "Autonomic dysfunction and hemodynamics in vitamin B12 deficiency". Autonomic Neuroscience 97 (1): 45–54. doi:10.1016/S1566-0702(01)00393-9. PMID 12036186. 
  10. ^ a b Lee C, Porter KM (Apr 2007). "Suspension trauma". Emerg Med J. 24 (4): 237–8. doi:10.1136/emj.2007.046391. PMC 2658225. PMID 17384373. 
  11. ^ "STEADI - Measuring Orthostatic Blood Pressure" (PDF). Centers for Disease Control and Prevention. Retrieved 20 December 2014. 
  12. ^ Logan, IC; Witham, MD (September 2012). "Efficacy of treatments for orthostatic hypotension: a systematic review.". Age and ageing 41 (5): 587–94. doi:10.1093/ageing/afs061. PMID 22591985. 
  13. ^ a b Izcovich, A.; Gonzalez Malla, C.; Manzotti, M.; Catalano, H. N.; Guyatt, G. (22 August 2014). "Midodrine for orthostatic hypotension and recurrent reflex syncope: A systematic review". Neurology 83 (13): 1170–1177. doi:10.1212/WNL.0000000000000815. PMID 25150287. 
  14. ^ Romero-Ortuno R, Cogan L, Foran T, Kenny RA, Fan CW (2011). "Continuous noninvasive orthostatic blood pressure measurements and their relationship with orthostatic intolerance, falls, and frailty in older people". J Am Geriatr Soc 59 (4): 655–65. doi:10.1111/j.1532-5415.2011.03352.x. PMID 21438868. 

External links[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Orthostatic_hypotension — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.

652 news items

Lodi News-Sentinel

Lodi News-Sentinel
Fri, 10 Apr 2015 08:34:54 -0700

Unless you actually faint, or have significant lightheadedness or dizziness, you will be dismissed, possibly for years. I'd like you to learn about the condition of low blood pressure, sometimes termed “orthostatic hypotension.” It's the opposite of ...

ProHealth

ProHealth
Tue, 21 Apr 2015 01:35:09 -0700

Some fibromyalgia patients have a condition called postural orthostatic hypotension. If you have this condition, aerobic exercise can harm you. Other studies suggest that some FM patients have a loss of heart rate variability. In other words, when you ...
 
Ocala
Tue, 07 Apr 2015 02:56:15 -0700

Yet you have trouble thinking, you're tired all the time and frequently feel cold. You probably “gray out” first thing in the morning when you get out of bed or stand up too quickly. When the nurse takes your blood pressure at your appointment and it ...
 
Tulsa World
Fri, 03 Apr 2015 22:03:05 -0700

Low blood pressure or “orthostatic hypotension” is equally bad, and it's a symptom of various problems including anemia, electrolyte imbalances, heart disease, adrenal insufficiency and Addison's disease, chronic Lyme disease, neurological dysfunction, ...

Pocono Record

Pocono Record
Thu, 16 Apr 2015 09:52:30 -0700

Some older people have a condition called orthostatic hypotension, which is an abrupt drop in blood pressure when they go from a lying or sitting position to a standing one. Other reasons for low blood pressure include heart problems, medications and ...
 
Herald & Review
Wed, 08 Apr 2015 23:56:15 -0700

Low blood pressure or “orthostatic hypotension” is equally bad and it's a symptom of various problems including anemia, electrolyte imbalances, heart disease, adrenal insufficiency, Addison's disease, chronic Lyme disease, neurological dysfunction, ...
 
PR Newswire (press release)
Mon, 20 Apr 2015 04:03:45 -0700

NEUPRO may cause symptomatic postural/orthostatic hypotension, and Parkinson's disease patients appear to have an impaired capacity to respond to postural challenge. Both Parkinson's disease and Restless Legs Syndrome patients treated with ...
 
PR Newswire (press release)
Mon, 13 Apr 2015 02:56:15 -0700

OXAYDO may produce orthostatic hypotension in ambulatory patients. OXAYDO must be administered with caution in patients in circulatory shock. Serious adverse reactions that may be associated with OXAYDO include: respiratory depression, respiratory ...
Loading

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight