What do the kidneys filter and then removes wastes?

The kidneys filter blood to remove waste products, excess substances, and toxins, including urea, creatinine, and various electrolytes. They maintain fluid and electrolyte balance by selectively reabsorbing needed substances while excreting the rest as urine. This process helps regulate blood pressure, pH levels, and overall homeostasis in the body. Ultimately, the kidneys play a crucial role in detoxifying the blood and maintaining internal stability.