What process do the kidneys primarily perform?

The kidneys primarily filter blood and produce urine, which is essential for maintaining the body’s homeostasis. This process involves the removal of waste products, excess nutrients, and excess water from the bloodstream, which are then excreted as urine. The kidneys play a critical role in regulating electrolyte balance, blood pressure, and the acidity of the body’s fluids, making their function vital for overall health.

Additionally, the kidneys contribute to other functions such as hormone production, but their primary role is to act as natural filters for the blood, ensuring that harmful substances do not accumulate in the body. This differentiates their function clearly from processes involved in digestion or temperature regulation, which are not primary functions of the kidneys.