Thirst and Dehydration
Thirsty? Then your body is on its way to becoming dehydrated.
The average adult has 10 to 12 gallons of water in his or her body, accounting for 60 percent of body weight. That water plays a critical role in nearly every bodily process. And being a quart or two low can affect how you feel.
“Water is needed by virtually every muscle or tissue cell,” says David K. Brennan, an exercise physiologist at Baylor College of Medicine in Houston. “Regulating body temperature is one of the most important roles water plays in the body. Without a plentiful supply of water, the body can have difficulty maintaining a normal temperature.”
Everything you do during the day—typing, talking, walking, eating— requires energy. That energy, in turn, generates heat, which escapes the body through perspiration. Perspiration keeps the body cool.
Most adults lose about 1.5 liters of fluid a day in urine. An additional liter is lost through breathing, sweating, and bowel movements.
So on an average day, you should be drinking lots of water. In addition, these are situations that require you to drink more liquid:
- Exercise Being in hot or humid weather Indoor heating during wintertime that causes dry air Being at a high altitude Illnesses that cause high fever, diarrhea, vomiting, or urinary tract infections Pregnancy or breastfeeding
Dehydration
Dehydration occurs when the body does not have as much water and fluids as it should. Dehydration can be caused by not drinking enough water or by losing too much fluid. Infants, children, the elderly, and people with certain illnesses are especially vulnerable to dehydration.The loss of just 2 to 3 percent of body-water weight can affect some of the functions in the body. Dehydration is classified as mild, moderate, or severe, depending on how much fluid is lost or not replaced. Mild or moderate dehydration can be treated by drinking small amounts of fluid; drinking too much too quickly can cause vomiting. Severe dehydration is a life-threatening emergency and requires medical treatment.
These are symptoms of dehydration that mean you should call your health care provider:
- Low or no urine output; concentrated urine appears dark yellow
- Lack of tears
- Sunken eyes
- In an infant, markedly sunken fontanels (the soft spot on the top of the head)
- Lethargic or comatose
