If you have to ask, you need to read this.

By Gabrielle Kassel/HEALTH.COM
Updated: Jan 18, 2019 @ 9:36 am
Getty Images

This article originally appeared on Health. For more stories like it, visit health.com.

You wash your hands after using the bathroom and soap up in the shower at least every other day. Maybe you even toss your pillowcase in the hamper a few times a week to prevent bacterial buildup that could result in breakouts.

But chances are there’s one thing you're not washing as often as you should: your bedsheets.

Don't feel bad. If the results of one small survey mean anything, most of us aren't washing our sheets enough either. According to the survey, women wait an average of 19 days to wash their bedding, while men hold off for 29 days, meaning their sheets get cleaned just once a month. Yikes.

The general rule of thumb is to wash your sheets once a week, no matter what you do or don't do in them. Because even when you sleep in head-to-toe pajamas, your bedsheets accumulate a nightly load of dead skin cells, sweat, dust, and possibly even small amounts of other bodily fluids.

Week after week, all these substances make for a nice environment where bacteria can thrive, Sherry Ross, ob-gyn in Santa Monica, California and author of She-ology. The Definitive Guide to Women's Intimate Health, tells Health. That sets you up to develop health issues such as rashes, breakouts, and allergies.

RELATED: Is Your Porn Habit Normal?

Exactly how often to wash sheets after sex

So you had sex—does that change the once a week rule? “If it’s a regular partner, change the sheets at least once a week—and more if there’s been obvious soiling,” Kim Langon, ob-gyn at family wellness site Parenting Pod, tells Health. By soiling, we're talking about a wet spot where your bodies were, goopy marks from lube, or even slight dampness after a super sweaty sex session.

These fluids can all breed bacteria, possibly triggering skin issues and infections. “If a woman is on her period there might be blood," Felice Gersh, ob-gyn and author of the upcoming PCOS SOS: A Gynecologist's Lifeline to Naturally Restore Your Rhythms, Hormones and Happiness, tells Health. "There’s probably semen. Saliva might be on the scene, along with sweat. There will be vaginal fluids.” There’s also the potential for fecal matter, if you took part in any anal play.

What if you had a one-night stand? Since you probably don't know anything about the person's hygiene habits, change the sheets after the hookup, just to be on the safe side. Dr. Gersh believes it also comes down to partner etiquette. No one wants to have sex in the same bed where another partner was not long before, whether they left behind any gross bodily fluids or not.

RELATED: Why Surrogacy Is Illegal in So Many Places 

Minimize the mess so you wash less

Of course, there's a simple trick to avoiding messing up your sheets so you don't have to haul ass to the laundry room: Lay down a towel on the bed (or couch, or floor) before you get down, which should absorb any fluids. Once you're done bumping and grinding, you can toss the towel and snuggle in your dry sheets. But if the towel gets gunked up, at least it's a lot easier to wash.

VIDEO: 5 Healthy Supplements Worth Your Money

The type of lube you use can also cut your laundry time. Avoid silicone-, petroleum-, and oil-based lubes, which tend to leave grease spots, and go with water-soluble brands, Mayla Green, co-founder of TheAdultToyShop.com, tells Health. If you do use a lube that isn’t water soluble and end up with stained sheets, she suggests saturating the area with dish soap before laundering in hot water.

Finally, if you have your period but are afraid of gushing all over your bed, you can always try the Period Sex Blanket, which is designed to absorb blood.