by Zoë Pollock
The classic metaphor has it all wrong:
Part of what makes you pee so much while boozing is that alcohol inhibits arginine vasopressin, also known as antidiuretic hormone or ADH. … Its job is to conserve water in the body by reducing its loss in urine. It binds to receptors on the kidneys and promotes water reabsorption, a decrease in the volume of urine sent to the bladder, and excretion of more concentrated urine. Alcohol throws a wrench into the works, though, and blocks certain nerve channels that help get ADH secreting out into your system. Without ADH carrying on about conserving water, the kidneys don’t reabsorb water as easily and excess water winds up getting dumped into urine to leave the body. With alcohol keeping ADH from doing its job, you produce a lot more water-diluted urine, which fills the bladder quickly and makes you have to pee more often.