The organ in the human body that filters blood is the kidneys. Each person has two kidneys, which are bean-shaped organs located on either side of the spine, just below the rib cage. The primary function of the kidneys is to remove waste products and excess substances from the bloodstream, thus helping to regulate blood pressure, electrolyte balance, and fluid balance in the body. The kidneys filter approximately 50 gallons of blood each day and produce urine as a waste product containing toxins, urea, and excess water. Proper kidney function is vital for overall health and homeostasis.