When you gotta go, you gotta go. And by “go,” I mean relieve yourself. You know…of urine. But sometimes — and we’ve all done this — you’ll hold your pee to finish one more email, or so you don’t miss the end of a movie, or just because you’re too lazy to walk to the bathroom from the couch. You’ve probably heard people say that that’s bad for you. And it is! But only if you do it frequently and for a really long time. And it almost always isn’t life-threatening. If you’re an adult, your bladder can hold up to about half a liter, or two full cups, of pee, before you’ll feel the need to … let it go, as Elsa might say.
Your bladder wall is lined with receptors that can measure how full your bladder is, and when it’s reached capacity, these receptors send your brain a signal that it’s time to hit the can. Most adults have control over their bathroom urges, meaning you can choose to pee right away after receiving these signals—or to hold it for a bit if you’re not near facilities. If you do decide to hold it, the cylindrical sphincters in your bladder close up tightly to keep all of the urine from leaking through your urethra.
But if you hold it in for long periods of time a lot—like if you’re a trucker who’s on the road for hours on end, for years—then you might find yourself facing some not-so-fun long-term effects, like urinary retention and increased risk of infection. Urinary retention is the inability to empty your bladder completely. Constantly holding in your pee can weaken your bladder muscles, which can be the cause of urinary retention as you age.
Your bladder can also become a breeding ground for bacteria if it’s constantly holding large amounts of urine, which slightly increases your chance of getting a bladder or urinary tract infection. Which sounds bad enough, but what if you held it in for longer? Think about Tycho Brahe, the 16th-century astronomer who supposedly died from a bladder that burst after he held his pee for too long? Well, long before you get anywhere near your bladder bursting, odds are your body will ignore your brain’s attempts to hold in the pee, and you’ll just wet yourself. However, in certain very rare, very extreme cases, bladders do burst.
When this happens, it’s almost always in people who already had a damaged bladder, like from a pelvic injury — though there are a few reports of bladders bursting in people who seemed perfectly fine before. In those cases, it’s generally because the person was been drinking a lot, and the alcohol dampened the signal to their brain that was telling them they needed to pee, like RIGHT NOW. But again, it’s incredibly rare. So if you do hold your pee in a few hours longer than you should, probably nothing super-terrible will happen. Unless you consider wetting yourself in public super-terrible. Totally understandable if you do!