What are diuretics and how do they work?
The amount of fluid (water) retained by the body is controlled primarily by the kidneys. This occurs due to the kidney’s ability to control the retention and elimination of sodium and chloride, because the amounts of sodium, chloride, and water in the body are carefully balanced. Thus, if sodium and chloride are eliminated from the body, water also is eliminated. Conversely, if sodium and chloride are retained by the body, so is water. The elimination of sodium, chloride, and water from the body is somewhat complex. In the kidneys, sodium, chloride, and other small molecules are filtered out of the blood and into the tubules of the kidney where urine is formed. Most of the sodium, chloride, and water are reabsorbed into the blood before the filtered fluid leaves the kidney in the form of urine. To make matters even more complex, there are different mechanisms that are active in different parts of the tubules that affect the reabsorption of sodium and chloride. Diuretics are a class of
