How does the body regulate water balance, and what role does Antidiuretic Hormone (ADH) play in this process?

Excess water intake: When you drink too much water, your body's fluid becomes diluted. This signals the brain to suppress ADH secretion. With less ADH, the kidneys reabsorb less water, leading to prompt water diuresis (increased production of dilute urine) to excrete the excess water and restore normal fluid concentration.

Water deprivation: When you don't drink enough water, your body's fluid becomes concentrated. This triggers two main responses:

• It provokes thirst, encouraging you to drink water.
• It stimulates ADH secretion. ADH acts on the kidneys to increase water reabsorption from the urine back into the bloodstream, leading to renal retention of water and a decrease in urine volume, thus conserving body water.