eli5/ why do we have such a tolerance for needing to pee when asleep?


if i am awake and drinking like I usually do i’ll pee extremely frequently and the accumulation of that fluid is never apparent when looking at me but when i wake up i have so much stuff to pee out that accumulated at the bladder that i look like I’ve just found out i’m pregnant why is it that if i tried to hold it in when i was awake i’d be in a great deal of discomfort but i don’t wake up in discomfort but am visibly swollen with fluid

In: 101

It would be dangerous to have your bladder highly full while moving around, because it has an increased chance of rupturing.

But when you are asleep you can afford to have it stretch out more without a big risk. So we evolved to be able to handle a greater degree of bladder stretching while sleeping.

A hormone called antidiuretic hormone, or ADH, causes the body to make less pee at night. But some people’s bodies don’t make enough ADH, which means their bodies may make too much pee while they’re sleeping.

As you age, that hormone gets less and less and you will wake up.

I mean, if you are drinking heavily and go to bed without peeing that is recipe for disaster. Or at least that’s what my friend told me.

It has to do with how heavily you sleep. The urge to pee gets stronger and stronger depending on how much the stretch receptors in the bladder are triggered, so the bigger the bladder, the more the discomfort. When you’re awake, even a little bit of stretch is uncomfortable and you want to relieve it. It’s a bit like being in an uncomfortable position. When you’re awake you shift until you’re comfortable, but if you roll into an uncomfortable position sleeping, it has to be really uncomfortable to wake you up immediately. Normally you don’t notice the discomfort until you wake up in the morning.

Drinking too much before bed is how you get pee dreams. Do you want pee dreams? Because that’s how you get pee dreams.

It might seem perfectly normal to be peeing into a football helmet full of Frosted Flakes while riding a flying bicycle made of licorice… but it’s a trap.