Washing your hands after you pee is probably something you do on autopilot. (Though if you’re someone who has trouble with hygiene tasks—like hand washing, brushing your teeth, and even showering—that’s okay, you’re not alone.) The thing is, it’s practically drilled into our heads that handwashing is one of the best ways to stay healthy and prevent the spread of germs, particularly after, ahem, doing your business. But sometimes when you’re in a rush (or just don’t feel like it), it can be tempting to skip the sink and move on. It can’t be that big of a deal, right?

Although it’s possible to leave a bathroom sesh without washing your hands and live to tell the tale, it’s not the best practice. The habit can increase your risk for various infections—so, of all the hygiene tasks to try to do regularly, this one tops the list. Not convinced? An infection prevention specialist explains just how important it is to wash your hands after peeing.

How germs spread in the bathroom

Germs can spread in myriad ways, according to the Centers for Disease Control and Prevention (CDC). Some germs are transmitted person-to-person via airborne droplets, while others are spread by touching contaminated surfaces.

Specifically, in a bathroom environment, germs are spread by the latter route. Your hands can pick up the little buggers while you’re peeing, wiping, and flushing, according to Hannah Newman, MPH, CIC, FAPIC, director of infection prevention at Lenox Hill Hospital. What’s more, every time the toilet flushes, microorganisms and particles of fecal matter become aerosolized (i.e., suspended in the air) and land on other surfaces like door handles, she says.

In other words, using the bathroom is one of the many ways germs can get on your hands. Taking 20 seconds to wash your hands with soapy water will effectively remove the germs. But is it actually dangerous if you don’t?

Why you should wash your hands after peeing

Here’s the thing: Many types of illness-causing bacteria can contaminate public and private bathrooms, says Newman. This includes E. coli, Salmonella, and Staphylococcus aureus, just to name a few microbes.

Many of these microorganisms can survive for several hours on inanimate surfaces, assuming the bathroom wasn’t just cleaned, explains Newman. “Others, such as norovirus, Clostridioides difficile, and hepatitis A, can survive for weeks or months,” she adds. For example, according to Newman, C. difficile—a gastrointestinal bacteria that cause nausea, vomiting, and diarrhea—has evolved to form spores or a protective “shell” that allows it to survive for up to five (yes, five) months.

Now, hopefully, you’re disinfecting your own bathroom more frequently than every five months. But the point is, the bathroom is like a party house for potentially harmful bacteria, making it easy for microbes to hitch a ride on your hands. This is especially likely in public bathrooms, which are often high-traffic areas that may or may not be cleaned regularly.

All that said, you should always wash your hands with soap and water after peeing, says Newman. It’s the best way to reduce the risk of getting sick or spreading germs to others. Post-pee handwashing is even more important “before preparing food, touching your eyes, nose, mouth, or face, or caring for people who are at risk of becoming ill,” adds Newman.

But what if you don’t plan on doing any of these things after peeing? It’s still wise to wash your mitts, each and every time, according to Newman. Otherwise, you may spread those germs to other surfaces (think: your keyboard, phone, or steering wheel), which you might handle before eating or touching your face later on.

How to properly wash your hands

During the height of the COVID-19 pandemic, proper handwashing was a particularly hot topic. But in case you need a refresher, Newman explains the right way to wash your hands:

1. 1.
   Wet your hands thoroughly; water temperature doesn’t matter, but avoid using very hot water, which can dry out your skin.
2. 2.
   Add enough soap, about a nickel-sized amount, to lather and cover your hands.
3. 3.
   Lather and scrub every part of your hands, focusing on hard-to-reach areas like under fingernails, between fingers, bottoms of your thumbs, and under jewelry.
4. 4.
   Scrub your hands for a minimum of 20 seconds.
5. 5.
   Rinse your hands well.
6. 6.
   Dry your hands using a paper towel.

While you’re at it, you can use the paper towel to turn off the sink and open the bathroom door to avoid recontamination of your freshly cleaned hands, says Newman.

If you can’t get to a sink, the CDC suggests using alcohol-based hand sanitizer with at least 60 percent alcohol. But keep in mind that, overall, handwashing with soapy water is always the way to go. As Newman notes, “alcohol can’t penetrate through spore-forming bacteria like C. difficile, so the physical friction of handwashing [will] remove those bacteria from hands.”

In short, it’s best to always wash your hands after peeing, especially before eating or touching your face. It might seem like a nuisance, but it’s one of the easiest ways to stay healthy and keep sickness at bay.