The hormone that helps in the reabsorption of water in the kidneys.

Antidiuretic hormone or vasopressin is the hormone that helps in reabsorption of water in the kidneys. ADH increases the water permeability of the cells by inserting aquaporin-2 at the end of distal convoluted tubule and collecting duct. Also, diuretic is any substance that causes water loss, therefore anti-diuretic prevents water loss.