For your body to function properly, your blood sugar levels need to stay within specific limits and shouldn't rise or fall too quickly.
When your blood glucose level rises too quickly (after eating a sugary snack, for example), your cells release water. This makes you unusually thirsty.
This is one of the reasons why sugary drinks don't really quench your thirst but instead make you want another glass.
It's very important to note that uncontrollable, unquenchable thirst can mean that your body can't cope with regulating its blood sugar levels on its own. If this sounds like you, make sure to see your doctor and get yourself checked for diabetes
. It's a simple, inexpensive test.