Causes
Some of the conditions that can result in extreme fluid loss are:
Gastroenteritis: If the gastrointestinal tract becomes infected or inflamed by a virus or bacteria that results in vomiting or severe diarrhea, dehydration may develop. Gastroenteritis usually does not last for more than 36 hours.
Cholera: Consuming water or foods that have been contaminated by human wastes infected with the cholera bacterium will cause vomiting and severe diarrhea and can lead to dehydration, hypovolemic shock, and, in some cases, death.
Excessive use of certain medications: Diuretics, also known as "water pills," stimulate the body to increase the rate and volume of urination and the loss of electrolytes (dissolved mineral salts such as sodium, potassium, and chloride) in the urine. Although problems are uncommon when diuretics are used and monitored properly, overuse combined with a low-salt diet may cause dehydration.
Bulimia: Bulimia nervosa is an eating disorder that involves uncontrolled or compulsive binge eating. Most often, the condition also involves purging through self-induced vomiting, laxatives, enemas, diuretics, or excessive exercising. All types of purging can result in dehydration.
Addisonian crisis: The adrenal gland, a gland located above the kidneys, produces steroid hormones that are involved in keeping the body's water in balance. Although it's rare, the adrenal gland can fail and cause a disease called Addison's disease, which can result in excessive loss of fluid and electrolytes and lead to dehydration.