The Scientist: Roger Sur, M.D., a urologist and director of the U.C. San Diego Comprehensive Kidney Stone CenterThe Answer: If you went to college you probably know what breaking the seal is. On a night of heavy drinking, party-goers will avoid going to the bathroom for as long as possible for fear of “breaking the seal” and having to go frequently after that for the rest of the night.For all the anecdotal evidence, there has yet to be a formal scientific inquiry of the phenomenon. It’s probably a myth, from a biological standpoint, but that isn’t to say there’s nothing to it. Let’s look at the facts. When you drink a lot, there are two main effects as far as your bladder is concerned: 1. You take in an unusually large volume of liquid, and 2. You introduce a powerful diuretic into your system—alcohol. That’s a recipe for the pee-pee dance.Your brain and heart have receptors to detect an excess of fluid in your bloodstream, like the excess fluid that comes from throwing back several beers. To reverse this volume overload, they release hormones, such as ANP (Atrial Naturetic Peptide), to start flushing the system. The kidneys, which are constantly regulating the water content of your blood, open up the gates to let more water pass through. But since that beer you drank is a diuretic, the gates don’t just open up a little bit—they fly open, directing a flood of water into the kidneys, where it is turned into urine and dumped into the bladder.Your bladder can hold around 300 to 400 cc of urine (that’s about as much as a red Solo cup filled to the third ridge). When it’s filled to capacity, nerves send a message to the spine, which communicates to the brain that it’s time to open the drain-stopping sphincter, contract the bladder muscles and empty out. That’s where things get tricky.Party wisdom dictates that you ignore that got-to-go feeling as long as possible, because if you pee now, you’ll spend the rest of the night in the bathroom line. That’s not completely off base. Your body is still trying to bail out the extra fluid, so your kidneys are going to keep filtering in overdrive and your bladder is going to fill up again—quickly. The truth is, you can’t stop the process; your system will fill and flush until it is back at equilibrium. By holding out, you’re only delaying the inevitable.MORE:Why You Have to Go in the Middle of the NightAlternatives to Kegels for Bladder ControlAre You Peeing Out Your Vitamins?UTIs: Fact and Fiction