How is fluid retained in the body; fluid retention

Ordinarily the body contains a certain amount of water which is distributed in the cells of the different structures that make up the body. Extra water is a problem. It may collect in or around the cells in small amounts, or it may collect in large amounts in the different body cavities. The word “edema” is used to describe extra fluid in the tissues beneath the skin; its presence is determined simply by pressing with the finger, in which case the indentation or pit remains. Fluid in the abdomen is called “ascites” and fluid in the chest is known as “hydrothorax.” When there is excess fluid everywhere in the body the term “anasarca” is used. One sign of excess fluid accumulation may be rapid gain in weight.

A variety of conditions may be responsible for these disturbances of handling of water by the body. The trouble may be with the blood, or the blood vessels, or the blood pressure. The difficulty may be in the composition of the tissues themselves There may be blocking of the flow of lymph. Finally, the kidneys play an important part in the elimination of fluid.

Actually the taking of an excess of water as fluids or in food is not the chief or important factor in water accumulation. Ordinarily the excess of fluid is simply eliminated by the kidneys, which can get rid of twenty times as much fluid as they usually eliminate. An excess of sodium or salt is more likely to cause accumulation of water in the body since the ability of the kidneys and sweat to get rid of excess salt is much less than for water. Since the adrenal glands are important in controlling the salt-water balance, disturbances of the action of these glands may be responsible for excess fluid in the tissues.

Swelling of one leg or arm is likely due to an obstruction of circulation affecting that organ. When both swell the difficulty is probably a general one. Swelling of eyelids and face in the morning is associated with insufficient protein intake.