Each night, your body sheds around 15 million skin cells, which build up if you don’t wash your sheets often. You’re essentially providing food for thousands of dust mites.
This is bad news for the some 20 million Americans who are allergic to proteins produced by dust mites and their feces.
If you never wash your sheets, fungi and bacteria build up, too. In fact, one study found that your pillowcase has more bacteria than your toilet seat.
Experts recommend washing your sheets once a week with the hottest water possible.
No one likes making their bed, let alone washing their sheets. Especially single men. In one survey, 55% of single men between 18 and 25 reported changing their sheets only four times a year. And to be clear, those are beds that you would not want to sleep in.
You shed about 15 million skin cells each night, but they don’t just pile up in your sheets. Because something else is already there waiting to gobble them up: dust mites. And the longer you wait between washes, the more food these critters will have and the more they’ll procreate and multiply. So if you don’t wash your sheets, you’ll be sleeping with hundreds of thousands of arachnids.
Now, for the estimated 20 million Americans with dust allergies, it gets worse. Dust mites and their feces produce proteins that cause red and itchy eyes, runny noses, and other cold-like symptoms in people who are allergic. And dust mites, well, they’re actually not the only allergen in a dirty bed.
If you never wash your pillow sheets, a community of fungus can also build up there. One study found that a typical pillow has as many as 16 different species of fungus and literally millions of fungal spores. And the most common among them, Aspergillus fumigatus, is potentially dangerous. In addition to allergic reactions, it can infect your lungs and other organs.
And it’s not just fungi joining the party. You see, bacteria also love a good unwashed pillow case or sheet a lot. Another study found that unwashed pillow cases and sheets had up to 39 times more bacteria than pet-food bowls and several thousand times more bacteria than a toilet seat. Like Staphylococcus aureus, which in some rare cases can be deadly.