No matter how high the thread count or how lovely the pattern, your pillowcase can harbour a lot of gunk, grunge, and other debris. Changing your sheets, which should be done at least once a week or at the most once in two weeks, is a must. But, if you want to be truly kind to yourself, or at least to your face, you should change your pillowcase at least once a week, if not more often.

Your pillowcase contains dust mites and their poop

Your entire body including your face is constantly shedding dead skin cells. Those dead skin cells accumulate on your pillowcase. And if you think that’s gross, wait until you see what comes next. Those cells, it turns out, are a favourite snack of microscopic dust mites, who feed on the delectable bits of dead skin right where you sleep.

Think again if you believe your home is free of dust mites. Dust mites are common in most homes, and the allergens they produce are derived from faecal pellets and body parts. Yes, dust mites leave a trail of poop and carcasses for you to roll your face in.

There’s More — Mucus, Dandruff, Ear Wax, and Saliva

Various types of body discharge can be transferred to pillowcases, sheets, clothes, towels, and other fabrics. Bodily secretions account for up to 70 percent of the dirt on your pillowcase. We produce and shed about one litre of sweat, 10 grams of salt, 40 grams of sebum and 2 billion dead skin cells on a daily basis.

It gets worse when you add in mucus, dandruff, earwax and saliva. If you wear makeup, facial moisturisers, sunscreens or hair care products which can rub-off on your pillowcase, there may be even more residue.

What this can do to your skin

All of that goop can cling to your skin, which is why pillowcases were created in the first place. If you slept on a ‘naked’ pillow, it could accumulate and transfer to your skin, causing skin irritation and acne breakouts.

And it doesn’t help if you have a pillowcase but don’t wash it. Soiled pillowcases can cause breakouts, especially if you have acne-prone or sensitive skin.

If you live with, and sleep with, a pet, you are adding to the list of potential irritants. Pet hair and dander on pillowcases can exacerbate allergies and eczema in people who are prone to these conditions. If you sleep with a pet, you should wash your pillowcases even more frequently.

If you can’t see the scum, try smelling it.

If your pillowcases appear clean but smell bad, this indicates that they aren’t truly clean. Body secretions and germs on your pillowcase are invisible to the naked eye but not to our noses. They cause an offensive stink.

A weekly wash is a good idea if you don’t want to aggravate the problem. Greasy body soils and dirt can become embedded between the fibres of your pillowcases, especially if they are not washed on a regular basis.