Thirst lets us know when the body needs more water. Thirst, however, isn't always a good guide for how much to drink. In hot weather or during exercise, a person needs to drink more than his thirst indicates. As people age, they have a reduced sense of thirst. It's important to pay attention to thirst and to take the time to get a drink.
Dehydration occurs when the body loses more fluids than it takes in.
Common causes of dehydration are fever, vomiting, diarrhea, lack of fluid intake, hot weather and heavy sweating. This is why you need plenty of liquids during an illness or hot weather. Symptoms of dehydration are fatigue, weight loss, dry skin, a decrease in urine output, rapid pulse rate and a dry mouth. Dehydration may be fast or slow, and sometimes requires a trip to the hospital. Mix orange juice and lemonade as directed on can.