Dehydration is the excessive loss of body fluids. Our bodies need a certain amount of fluid daily to maintain all the body systems with the minimum considered to be 4 glasses of fluid per day (the ideal amount is considered to be 8 glasses). However, basic requirements will vary with your age and the amount of activity you undertake. Very active people may need 2 to 3 times the normal limit.
If we lose more fluid than we replace the result is dehydration. Normally, the fluid depletion is signalled by thirst and is replenished by drinking. If the fluid lost is not replaced within a few days, severe dehydration develops, and can lead to changes in the body’s chemistry, kidney failure and may even be fatal. This severe form of dehydration is considered a medical emergency.
There are also a number of conditions, types of surgery and medications that can cause dehydration.
Your doctor can determine the cause of dehydration and treat it, and may admit you to hospital for the administration of intravenous fluids if dehydration is severe.
Dehydration can be prevented by drinking plenty of fluids if you are in a hot climate, participating in strenuous exercise or suffering from diarrhoea. If you are vomiting uncontrollably, try to sip small amounts of fluid in between bouts.
Last Reviewed: 11 July 2001