Dehydration - meaning of word
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Dehydration



Dehydration is the removal of water (''hydor'' in ancient Greek language) from an object. Medically, dehydration is a serious and potentially life-threatening condition in which the body contains an insufficient volume of water for normal functioning. In non-medical usage, there are many methods of dehydration, with the most common being the application of dry heated air. This causes evaporation of the surface water, which is replaced by water internally. Drying (food) is often used as a method of food preservation and is also used to obtain absolute alcohol. ==Medical causes of dehydration== In humans, dehydration can be caused by a wide range of diseases and states that impair water homeostasis in the body. These include: * external or stress-related causes ** blood loss or hypotension due to physical trauma ** diarrhea ** hyperthermia ** shock ** prolonged physical activity without consuming adequate water, especially in a hot environment ** survival situations, especially desert survival conditions ** vomiting * infectious diseases ** cholera ** gastroenteritis ** shigellosis ** yellow fever * malnutrition ** electrolyte imbalance *** hypernatremia (also caused by dehydration) *** hyponatremia, especially from restricted sodium chloride diets ** excessive consumption of ethyl alcohol ** fasting ** patient refusal of nutrition and hydration * other causes of obligate water loss ** severe hyperglycemia, especially in diabetes *** glucosuria ==Symptoms and prognosis== Symptoms may include headaches similar to what is experienced as a hangover, decreased blood pressure (hypotension), and dizziness or fainting when standing up due to orthostatic hypotension. Untreated dehydration generally results in delirium, unconsciousness, and death. Dehydration, along with starvation, is commonly viewed as a very unpleasant way to die. ==Treatment== Correction of a dehydrated state is accomplished by the replenishment of necessary water and electrolytes (rehydration). Even in the case of serious lack of fresh water (''e.g.'' at sea or in a desert), drinking seawater or urine does not help, nor does the consumption of alcohol. When dehydrated, unnecessary sweating should be avoided, as it wastes water. If there is only dry food, it is better not to eat, as water is necessary for digestion. ==Avoiding dehydration== A person's body loses, during an average day in a temperate climate such as the United Kingdom, approximately 2.5 litres of water. This can be through the lungs as water vapor, through the skin as sweat, or through the kidneys as urine. Some (a less significant amount, in the absence of diarrhea) is also lost through the bowels. When taking vigorous exercise or in a hot environment, it is easy to lose twice this amount. Heavy exercise in high temperatures could cause the loss of over 2.5 litres of fluid per hour, which exceeds the body's absorptive capacity. ==Ethical concerns== Judge Lynch of the Massachusetts Supreme Judicial Court argued that death by dehydration symptoms was ‘"cruel and violent"’ in his opinion on the 1986 Brophy case: *The mouth would dry out and become caked or coated with thick material. *The lips would become parched and cracked. *The tongue would swell, and might crack. *The eyes would recede back into their orbits and the cheeks would become hollow. *The lining of the nose might crack and cause the nose to bleed. *The skin would hang loose on the body and become dry and scaly. *The urine would become highly concentrated, leading to burning of the bladder. *The lining of the stomach would dry out and the sufferer would experience dry heaves and vomiting. *The body temperature would become very high. *The brain cells would dry out, causing convulsions. *The respiratory tract would dry out, and the thick secretions that would result could plug the lungs and cause death. *At some point within five days to three weeks, the major organs, including the lungs, heart, and brain, would give out and the patient would die. ==External links== *[http://www.uga.edu/nchfp/how/dry/dehydrator.html National Center for Home Food Preservation - Food Dehydrators] *[http://www.acs.ucalgary.ca/~smzess/survival/water.htm Tips from the SAS Survival Guide by John Wiseman] *[http://www.safetycenter.navy.mil/media/approach/issues/mar02/cool.htm Report of a navy officer including some tips] *[http://www.ivillage.co.uk/health/hlive/eat/articles/0,,181168_588681,00.html Are you drinking too much water?] ==References== * Ira R. Byock, M.D., ''[http://www.dyingwell.com/prnh.htm Patient Refusal of Nutrition and Hydration: Walking the Ever-Finer Line]''. American Journal Hospice & Palliative Care, pp. 8-13. (March/April 1995) Electrolyte disturbance Nutrition

Dehydration



:Ideally, at least two litres (approximately eight glasses) of pure water should be consumed per day. This is in addition to other fluids,such as alcohol, tea, coffee and many soft drinks, that may increase loss of or need for water. This sounds like some kind of bottled water advertisement. In most places no sane person ever drinks that much water. The first approximation of daily water requirements, as found in most medicine textbooks, is about 550 ml (gain with metabolism - loss with respiration - loss with perspiration) + loss with urine (without excessive heat, physical effort etc.), with the latter variable in a very wide range. Most of the food contains a lot of water. About any common drink, except for those with extremely high alcohol content, provides much morewater than it causes to loss with increased urination. So usually you don't need to drink any "pure water" at all, and only a limited amount of other drinks – much less than the 2 litres a day. User:Taw 10:42, 2 Sep 2004 (UTC)


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Words begining with Dehydration:

Dehydration
Dehydration
Dehydration_reaction
Dehydration_synthesis


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