The kidneys perform one of the finest balancing acts in nature: they maintain the blood’s pH level, vital to your body’s health. The relative acidity or alkalinity of a liquid is called its pH. Your blood needs to be in a narrow range of pH, slightly alkaline, but close to neutral.

To help maintain that level, the kidneys provide the blood with a buffer solution that compensates for any rise or fall in the level of acidity or alkalinity caused by diet or stress. They do this by adjusting the amount of fluids and vital salts, called electrolytes, in your blood. These electrolytes include sodium, potassium, calcium, and other substances. Your kidneys also produce the hormone renin, which helps to control blood pressure.