hormonal and metabolic disorders
About Body Water
Introduction
Water accounts for about one half to two thirds of an average person’s weight. Fat tissue has a lower percentage of water than lean tissue and women tend to have more fat, so the percentage of body weight that is water in the average woman is lower (52 to 55%) than it is in the average man (60%). The percentage of body weight that is water is also lower in older people and in obese people. The percentage of body weight that is water is higher (70%) at birth and in early childhood. A 154-pound (70-kilogram) man has a little over 10.5 gallons (42 liters) of water in his body: 7 gallons (28 liters) inside the cells, 2.5 gallons (about 10.5 liters) in the space around the cells, and slightly less than 1 gallon (3.5 liters, or about 8% of the total amount of water) in the blood. Water intake must balance water loss. To maintain water balance—and to protect against Dehydration , the development of When the kidneys are functioning normally, the body can handle wide variations in fluid intake. Thebody obtains waterprimarily by absorbing it from the digestive tract. Additionally, a small amount of water is produced when the body processes (metabolizes) certain nutrients. Thebody loses waterprimarily by excreting it in urine from the kidneys. Depending on the body's needs, the kidneys may excrete less than a pint or up to several gallons (about half a liter to over 10 liters) of urine a day. About 1½ pints (a little less than a liter) of water are lost daily when water evaporates from the skin and is breathed out by the lungs. Profuse sweating—which may be caused by vigorous exercise, hot weather, or a high body temperature—can dramatically increase the amount of water lost through evaporation. Normally, little water is lost from the digestive tract. However, prolonged vomiting or severe diarrhea can result in the loss of a gallon or more a day. Usually, people can drink enough fluids to compensate for excess water loss. However, people who have severe Nausea and Vomiting in Adults or Mineral salts ( Overview of Electrolytes ), such as sodium and potassium, are dissolved in the water in the body. Water balance and 