Why You Have To Pee More At Night As You Age, From An MD

"The antidiuretic hormone, ADH, or vasopressin, decreases with age," says Cohen.

Let's put ADH in context: the chemical's main job is to control how much water your body is saving – when these levels are high, your body will produce less urine. And levels tend to go up during the night to keep you from wetting the bed. "The idea is that we don't get up at night to pee," added Cohen.

If ADH naturally decreases as you age, it means these levels can stay low while you sleep – and you may feel the urge to get up and walk.

The exact age is difficult to say. After all, every body is different. Studies have reported these changes in people aged 65 and over, but again, there is no specific year. If you're under 65, "unless you have a big glass of water in the middle of the night, you're probably still young enough," notes Cohen.