If it’s never occurred to you to wonder, Huh, how often should I change my pillowcase?, we can’t really blame you. You’d probably much rather associate your pillowcases—and pillows themselves—with comfort and sleep than with laundry. Unfortunately, if you don’t swap out your pillowcases often enough, you might be unknowingly messing with your pillow’s potential to be a key part of your bedtime oasis. Below, we talked to experts to learn just how often you should wash your pillowcases (and the actual pillows themselves).
So what exactly is lurking on your pillowcase?
According to the American Academy of Dermatology (AAD), we humans shed between 30,000 and 40,000 skin cells every day. When you spend at least seven hours (hopefully) sleeping, you’re shedding many of those skin cells right onto your sheets and pillows. On top of that, sweat, oil from your skin (especially if you don’t wash your face before bed), and good ol’ fashioned drool are all going to end up on your pillowcases as well. You might even end up with allergens (like pollen) in your bed via your hair, if you’re not a nighttime showerer. And let’s not forget the skin cells, sweat, oil, and drool of your partner and/or pet, if you share a bed with them.
All those cells and bodily fluids can cause microorganisms—like bacteria and fungus—to grow. This isn’t likely to have a significant bearing on your health, but it can lead to skin irritation, breakouts, and possibly even infections. Thomas A. Russo, M.D., professor and chief of infectious disease at the University of Buffalo Jacobs School of Medicine & Biomedical Sciences, tells SELF that while fabrics like pillowcases and sheets can potentially be contaminated, they aren’t generally ideal places for most microorganisms to grow and propagate effectively.
Very contagious skin infections like staph or ringworm can theoretically transmit between two people via bed linens, Dr. Russo says. But it’s very difficult to know if something spread that way or was transmitted simply from skin-to-skin contact if two people are living together and intimately close.
Even though the risk of spreading infectious bugs via your sheets is slim, the microbes that regularly build up on your pillowcase can disrupt your skin’s delicate balance of microbes, called the microbiome, which can cause breakouts if you have acne-prone skin, SELF previously reported. If you have eczema, it can potentially lead to a flare.
Now, let’s talk dust mites.
Dust mites, which are too small to see without a microscope, are teeny tiny creatures that live in household dust and feast on dead human skin cells. They thrive in warm, humid environments, and especially love living in bedding—where they enjoy an endless supply of sloughed off skin cells. Yummy.
These critters are NBD if you’re not allergic to them. If you are, they can be a huge deal. “Dust mites are by far the most pervasive indoor allergen,” board-certified allergist-immunologist Ryan Steele, D.O., assistant professor of clinical medicine at Yale School of Medicine and program director of the Yale Allergy & Immunology Contact Dermatitis Program, tells SELF. “Dust mites are something we think of as affecting airways and causing nasal congestion and watery eyes, but they can also make your skin itchy and worsen eczema.”
There’s not really any way to get rid of or prevent dust mites, Denisa E. Ferastraoaru, M.D., assistant professor of medicine in allergy and immunology and attending physician at Einstein/Montefiore and Jacobi Medical Centers, tells SELF. So allergists advise patients with dust mite allergies to get allergy covers for their pillows (and mattress and comforter). “Covers basically keep dust mites inside the pillow/bed so that we can’t breathe them in,” Dr. Ferastraoaru says. If you can put a dust mite cover on any new pillows before using them for the first time, you can also keep dust mites out in the first place.
So, how often should you change your pillowcase?
The best and easiest way to prevent potential skin issues? Wash or change your pillowcases and allergy covers regularly. Dr. Steele suggests doing so once a week, and if washing, using the hottest setting you can to kill microbes and allergens. If you’re a big-time drooler or make it a habit of going to bed with makeup on, you may want to wash or change your pillowcases more often.
On that note, washing your face every night and showering before bed (especially if you got super sweaty or have seasonal allergies) will help keep your pillowcases cleaner for longer.
What about the actual pillows?
The National Sleep Foundation recommends washing pillows (if you can) every six months with hot water and mild detergent. That’s right, many pillows can actually be washed! And it turns out…you should be doing that! Generally, down/feather pillows and down-alternative pillows can go in the washing machine on the gentle cycle; while most foam pillows shouldn’t be machine washed. Some pillows may do best when dry cleaned. Make sure to read the manufacturer’s instructions for your specific pillow.
When it comes to replacing your pillows, the National Sleep Foundation suggests swapping out pillows with new ones that aren’t full of dust mites and sweat every one to two years.
Now, that’s not a hard-and-fast rule, and if buying new pillows yearly sounds like a hefty expense, you’re not wrong. By using allergy covers and washing your pillowcases, covers, and pillows as regularly as you can, you’ll keep them in good shape for longer and buy some time before their dustiness, mustiness, and/or lack of fluffiness get between you and a peaceful night’s sleep. Because that’s what it’s all about, after all.