Osmoregulation is the regulation of the osmotic pressure of bodily fluids. It keeps the body's fluids from becoming too dilute or too concentrated. Osmotic pressure is the movement of water from one solution to another.

The kidney plays a very important role in this process. It regulates the amount of water in urine waste. The body naturally produces hormones with which the human body can increase the permeability of the collecting ducts in the kidney to stop the water from being excreted, instead reabsorbing it back into the body.