Why does alcohol always leave you thirsty? The science behind the dry mouth

There’s a familiar moment that arrives halfway through a drink, or sometimes the morning after. Your mouth feels oddly dry. Water suddenly looks irresistible. You might not feel drunk anymore, but your body is clearly asking for something it’s missing. Most people chalk it up to “hangover stuff” and move on. But the thirst isn’t incidental. It’s a direct response to how alcohol interferes with the body’s most basic systems for managing water. Alcohol is a liquid, but it doesn’t behave like one once it’s inside you. Instead of topping up your reserves, it quietly tells your body to let go of them. Under normal conditions, your body is careful with water. A hormone called vasopressin, also known as antidiuretic hormone, helps regulate how much fluid your kidneys keep and how much they