Dehydration is the excessive loss of water from the body. Water can be lost through urine, sweat, feces, respiration, and through the skin. Symptoms of dehydration in order of severity are: thirst, nausea , chills, clammy skin, increased heart rate, muscle pain, reduced sweating, dizziness, headache, shortness of breath, dry mouth, fatigue , lack of sweating, hallucinations, fainting, and loss of consciousness. Dehydration can affect mental alertness, renal function, circulation, and total physical capacity.
The following can help to avoid dehydration:
- Drink before feeling thirsty
- Drink enough fluid to have pale yellow urine
- Avoid caffeine and alcohol, which act as diuretics
- Drink two to three cups of fluid two hours before exercise or heavy outside work in hot temperatures
- Drink one to two cups of fluid every fifteen minutes during exercise or heavy outside work in hot temperatures
- Avoid exercising during midday heat, and wear appropriate clothing that allows airflow around the body
Athletes, elderly persons, young children, and those with specific illnesses that affect fluid balance, such as severe diarrhea, are at higher risk for dehydration than the average person.
Dorland's Pocket Medical Dictionary, 23d edition (1982). Philadelphia: W. B. Saunders.
Berning, Jacqueline R., and Steen, Suzanne Nelson (1998). Nutrition for Sport and Exercise, 2nd edition. Gaithersburg, MD: Aspen.