How Often You Should Wash Your Sheets (and the Gross Reasons Why)

If changing your bed sheets is at the bottom of your household chore list (you know, right along with matching socks and scrubbing the shower’s grout), consider this: You’re not sleeping alone. Joining you in bed are countless dust mites and bacteria, not to mention lots and lots of your own dead skin.

Dermatologist Alok Vij, MD, says you should wash your sheets at least every two weeks — maybe more, depending on factors like whether you live in a warm climate and whether your pet sleeps in your bed.

Dr. Vij talks dead skin, dust mites, bed bacteria and how to keep your skin safe when you lie down to sleep.

Why you need to wash your sheets

Even when you think you’re sleeping alone, you’re actually joined by an array of strange bedfellows that are invisible to the naked eye — and they can cause skin problems like rashes and eczema, not to mention asthma and allergies.

Here’s a look at what else is in bed with you, and what issues they can cause.

Dead skin

Rolling around in your own discarded skin, anyone?

According to Dr. Vij, the average person sheds a gram and a half of keratinocytes (largely made up of the protein keratin) daily. Visually speaking, that’s almost half a teaspoon full of dead skin.

“Any kind of friction will chafe off the outer layer of your skin cells,” he explains, “so, a lot of it is shed when you’re making contact with your sheets in your bed at night.”

Bacteria

When dead skin cells are left to rest in your sheets, bacteria thrive. These skin cells act as a breeding ground for bacteria to make themselves at home on your sheets, mattress and pillows.

“Bacteria love skin so much that there are actually more bacterial organisms in our bodies than our own cells,” Dr. Vij says. And the skin is one of bacteria’s most commonly inhabited areas.

Dust mites

Dust mites are too small to be seen by the naked eye, but they live on every continent on Earth except Antarctica. These teeny-tiny, eight-legged critters are relatives of the spider, and they feed on dead skin cells — your dead skin cells.

As many as 1 million dust mites can feast on the dead skin you produce in a mere day. They don’t bite, like bed bugs do (in fact, they don’t even have teeth or mouths), and they don’t burrow under your skin, like scabies do, but they can still cause you some unwanted health issues (more about that in a minute).

Pet dander (and more)

If you let your cat or dog sleep in the bed, take note: Your four-legged friends are also harbors for fungal organisms that can cause skin issues in humans.

These include simple infections like ringworm, as well as more aggressive infestations such as scabies, which are caused by mites that can live on dogs and be transmitted to people.

“There are a number of other parasites, too, that can be transferred from pet to pet parent, so make sure you’re washing your sheets often,” Dr. Vij advises.

What else is in bed with you?

Other icky stuff in bed with you may include:

• Bodily fluids: The average person produces 26 gallons of sweat in bed every year. And don’t forget about other fluids like oil and saliva.
• Beauty products: Even if you wash your face at night, you can still bring bits of makeup, lotions and more into bed.
• Crumbs: If you eat in bed (and sometimes, even if you don’t), you can bring little bits of food into the sheets with you at night.
• Other pet-related germs: In addition to dander and mites, your pets can track things into bed on their paws, including feces, litter and dirt from outdoors.

All of these give bacteria more excuses to survive and thrive, all while you’re getting a good night’s sleep in their midst.

What can happen if you don’t wash your sheets?

You might not mind sharing your sleeping spot with itty-bitty bedmates, but they can still present a variety of problems.

• Allergic symptoms: Many people are allergic to dust mites, so sleeping in a bed full of them can result in allergy symptoms. “Dust mites can lead to itching and trigger asthma flare-ups and seasonal allergies,” Dr. Vij notes.
• Breathing issues: If you already have asthma, you’re more prone to a dust mite allergy. But even if you don’t, sharing your bed with these little guys can bring on symptoms like wheezing and whistling.
• Rash: “If too many dust mites come in contact with your body, you can end up with a rash,” Dr. Vij adds. Some bacteria can cause rashes, too.
• Eczema: Eczema is one of the most common types of skin rashes, driven by a combination of the dryness of your skin and overactive bacterial colonies on your skin. “By allowing bacteria to live in harmony on your sheets and get on your skin when you hop in bed, you could be making your eczema worse — or allowing it to start in the first place,” he says.
• Folliculitis: When you lie down in a bacteria-laden bed, you open yourself up to folliculitis, an inflammation, infection or irritation of the hair follicle.

What about other types of bedding?

Good news: Your other bedding isn’t as high-maintenance as your begging-to-be-washed sheets.

“Blankets and pillows don’t need to be washed as frequently,” Dr. Vij states, “but skin cells, bacteria and dust mites can definitely travel and live on your pillow or in your blanket, so make sure they’re part of your cleaning rotation.”

For those items, every six months or so should do the trick. And if your kids sleep with blankies or stuffed animals, make sure you add them to your to-wash list, too, as they can be hotbeds for dust mites and bacteria.

Who should wash their bed sheets more frequently

If you sleep alone, don’t have pets and live in a climate-controlled home, you can probably get away with washing your sheets every two weeks. But some people should wash them more often — like, once a week.

You should consider changing your sheets on a weekly basis if you:

• Have pets, especially if they sleep in your bed.
• Live in a very hot climate.
• Sweat a lot in your sleep (like if you’re experiencing hot flashes).
• Are recovering from an illness or infection.
• Have allergies or asthma.
• Sleep naked.

How to keep your bed as clean as possible

Ultimately, Dr. Vij says the risk of getting a bad bacterial infection under your skin is pretty low. “Still,” he continues, “it’s a good idea to practice good bed linen hygiene so your bacterial ecosystem doesn’t get out of whack.”

Here are some tips for keeping your bed clean:

1. Change your bedding regularly. Swap out your sheets for clean ones every one to two weeks. Everything else (like your comforter, pillows, etc.) can be washed every six months or so.
2. Wash with hot water. When you wash your bedding, it’s best to use hot water, which kills off dust mites and helps get everything thoroughly clean.
3. Don’t make your bed! Consider this your excuse to leave the bed unmade for a little while each morning. Give sweaty sheets a chance to dry by not pulling up your comforter ASAP. “This will reduce the moisture that dust mites and bacteria need to flourish,” Dr. Vij says.

And if possible, try not to think about it as a chore. It always feels great to slide into clean sheets, and washing them has another substantial upside, too.

“The washing process fluffs your pillow and distributes your blanket’s filling more evenly,” Dr. Vij says. “That’s helpful for making your pillows and blankets as comfortable as possible for their whole life.”