Body Water Balance, Intake and Outlet/loss of Body Water.

Water is the main constituent of the body, about 60-70% of the total Body Weight consists of Water.  The water content of Soft Tissues ranges from 70-80%, while that of bone about 20 percent approximately.

Body Water is distributed as follows:

• Intracellular water (ICW), which present Inside the cells of tissue
• Extra cellular water (ECW), are Outside the tissue cells

The Extra cellular water (ECW) is further subdivided into:

• Water in blood plasma.
• Interstitial water – water in tissue space.
• Lymph in the lymphatic vessels.

Intake and Outlet/loss of Water.

Water is taken in food and also as drinking water.  In addition, water is formed in the tissues by the oxidation of hydrogen present in proteins, carbohydrates and fats. 

Water intake varies widely depending on the climate; as drinking water about 1500-5000 ml and in food 1000-2000 ml.

Water is lost continuously from the body in the following ways: 

• Through kidney as Urine.
• Through insensible perspiration and as sweat.
• Through the lungs in the expired air.
• Through the large intestines in the faeces.
• In lactating women in the milk.

Body Water Loss varies depending on the climate: in urine, about 100-1500 ml, through skin 800-5200 ml, through lungs 400 ml and in faeces 100-200 ml.  In a normal individual, the water intake is approximately equal to water lost from the body and the water content of the body is maintained fairly constant.

Effect of Excess and Loss of Water on Water Balance?