The kidneys filter waste products and excess fluids from the blood to produce urine. Each kidney contains about a million nephrons, which filter blood, reabsorb useful substances, and excrete waste. The filtered urine passes through ureters to the bladder and is eventually expelled through the urethra.
Kidneys also regulate blood pressure, electrolyte balance, and red blood cell production. Healthy kidney function is essential for maintaining internal chemical balance and removing toxins from the body