what is the job of kidneys

The kidneys are responsible for several important functions in the body, including:

1. Filtering waste and excess substances from the blood, such as toxins, urea, and other waste products produced by metabolism.
2. Regulating the balance of electrolytes, such as sodium, potassium, and calcium, in the blood.
3. Controlling the body's fluid balance by regulating the amount of water excreted in the urine.
4. Producing hormones that help regulate blood pressure, stimulate red blood cell production, and maintain bone health.

Overall, the kidneys play a crucial role in maintaining the body's internal environment and ensuring that waste products are efficiently removed from the bloodstream.