Kidneys are bean-shaped, vital organs in the excretory system, made of millions of tiny units known as nephrons and tubule that help in reabsorption of certain substances and removal of toxic chemical fluids from the body, which are formed during breakdown of food we eat as well as from other metabolic activities.
One of the main chemicals that kidneys filter is “urea”. Urea is formed by the breakdown of proteins in the liver. It is not required by the body and is, in fact, toxic for the body. The kidneys convert urea into urine, which gets removed from the body finally. The kidneys also filter drugs and excess of Sodium, Potassium from the blood. They also secrete chemical substances- hormones that regulate the blood pressure.