Balancing fluid levels

By removing just the right amount of excess fluid, healthy kidneys maintain what is called the body's fluid balance.

In women, fluid content stays at about 55% of total weight. In men, it stays at about 60% of total weight. The kidneys maintain these proportions by balancing the amount of fluid that leaves the body against the amount entering the body.

Fluid comes into our bodies from what we drink, and from high-liquid foods such as soup. If we drink a lot, healthy kidneys remove the excess fluid and we pass a lot of urine. If we don't drink much, the kidneys retain fluid and we don't pass much urine.

Fluid also leaves the body through sweat, breath, and feces. If the weather is hot and we lose a lot of fluid by sweating, then the kidneys will not pass so much urine.

As your kidneys fail, maintaining this balance becomes more difficult. You may suffer symptoms of too much fluid. You may need to watch your diet and what you drink to maintain fluid balance.