What is ADH? What are its functions?

Antidiuretic hormone (ADH) is one of the hormones that efficiently monitors and regulates the functioning of the kidneys. Antidiuretic hormone released from the posterior pituitary, prevents wide swings in water balance, helping to avoid dehydration or water overload. ADH facilitates reabsorption of water by the distal parts of the kidney tubules and thereby prevents diuresis.