Dehydration occurs when a person loses more fluids than he or she takes in, interfering with the body's normal functioning. Dehydration can be caused by inadequate fluid intake during strenuous exercise, in very hot weather, and during an illness. It is important to drink more liquids in these situations to compensate for the body's fluid loss. Fortunately, preventing dehydration can be simple under normal circumstances. Most healthy people should simply drink water or another beverage when they are thirsty and drink more during times when they lose more fluids.
Exercise is usually beneficial for a variety of reasons and may improve overall health. Strenuous workouts, however, cause the body to sweat and lose water and electrolytes. This is especially true if exercise happens in very hot weather or even in cold weather if a person is sweating under heavy clothing. Ideally, people should make sure they are well hydrated before a workout and consume fluids regularly both during and after. It is important to drink enough even if you don't feel thirsty, as sometimes dehydration can occur without any apparent symptoms.
Being outdoors in very hot weather can elevate the body temperature and cause a person to sweat more than usual, and even mild activity can cause fluid loss. Very dry indoor air or high altitudes can also accelerate moisture loss. Some people, such as children and the elderly, are even more susceptible to dehydration in warm temperatures. Preventing dehydration in hot weather may require people to drink more water on a more regular basis than they normally would. Staying out of the sun as much as possible and avoiding strenuous activity can also help to minimize moisture loss under these conditions.
Dehydration can also occur during illnesses that cause vomiting or diarrhea. Liquids should be given regularly as soon as possible after a person is able to keep them down. Doing so can help in preventing dehydration, as a great deal of fluid is lost from the body from vomiting and diarrhea. Parents may need to observe sick children carefully for signs of dehydration, especially in very young children who cannot verbalize their symptoms. Although sodas like ginger ale are sometimes recommended to settle the stomach, they contain a lot of sugar and not enough electrolytes to provide adequate hydration.
Although preventing dehydration is important for overall health, it is possible to consume too much fluid. This causes a potentially life threatening condition called hyponatremia, in which the body's sodium levels are too low. Taking in only enough to compensate for fluid loss is the best way to maintain a healthy balance.