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Listening to a bubbling stream can be pretty relaxing, up until the point when you realize you suddenly have to pee.

Hosted by: Michael Aranda
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[SciShow intro plays]
[text: QQs: Why does running water make you want to pee?]

Michael: Listen to this. [water flowing] The sound of a bubbling stream can be pretty relaxing. But, can I ask a personal question...? Do you kinda have to pee now? ‘Cuz if you do, you’re not alone. Just the sound of running water -- whether it’s a leaky faucet, some light rain, or a gushing waterfall -- sends some people running for the nearest bathroom. But why?

Psychologists and urologists, or scientists who study the urinary tract, chalk it up to the power of suggestion. Basically: running water kind of sounds like urination, so just hearing the noise can make you feel like you need to pee. This sort of unconscious association is called a, and the psychological theory behind it has been around for a while. In fact, you’ve probably heard of this classic example -- the Russian physiologist named Ivan Pavlov and his experiments with dogs.

Pavlov would set some delicious meat powder in front of a dog, and it would start salivating -- which is a normal doggy reaction to food, or an unconditioned response. And then, he would ring a bell, and feed it. After repeating this for months, Pavlov could ring the bell without offering any meat powder, and the dog would still start drooling. So his pup had learned to associate a specific sound -- the bell -- with a specific act -- being fed, and began slobbering -- that was its conditioned response.

This same effect could explain our strange peeing urges. Ever since potty training, we learn to associate the sound of running water with urinating and other bathroom sounds like flushing a toilet and washing our hands. So instead of hearing a bell, being reminded of food, and drooling... we hear running water, are reminded of all things bathroom, and need to pee. That’s the theory at least.

The thing is, this phenomenon hasn’t been officially studied in much detail, so scientists aren’t positive that this is the whole cause. But it is a pretty common thing. In fact, doctors have successfully used running water sounds to help prostate surgery patients and people with paruresis [par-you-REE-sis] -- also known as “shy bladder syndrome” -- to turn on the waterworks.

Some researchers even think this power of suggestion isn’t limited to audio cues -- so even just looking at pictures of gushing waterfalls could give you the urge to pee. But that’s enough urine talk for now. We’ll wrap up, in case some of you need to take a bathroom break.

Thanks to Patreon patron Dr. Carbon for asking this question, and thanks to all our patrons, who keep these answers coming. If you’d like to submit a question to be answered, or get these Quick Questions a few days before everyone else, just go to And don’t forget to go to and subscribe!