You might think your pillow is a cozy, innocent place to lay your head at night. But lurking beneath that fluffy exterior, there could be a miniature zoo of gross microbes and creepy-crawlies making themselves at home. From dust mites to fungus, the average pillow is a breeding ground for some seriously icky stuff. But don’t lose sleep over it just yet – we’ve rounded up all the dirty details on what’s hiding in your pillows, and when it’s time to toss those nasty old headrests for good.
1. Dust Mites Galore
Those microscopic bugs known as dust mites absolutely love making their home in your pillows. They feed on the dead skin cells and oils that slough off your body as you sleep, so your pillow is like an all-you-can-eat buffet to them. One study found that the average pillow can contain up to 16 different species of fungus and literally millions of fungal spores.
While dust mites themselves don’t bite or cause disease, their feces contain an allergen that can trigger asthma, sinus problems, and other respiratory woes in sensitive people. One in five people have allergies aggravated by dust mites. If you want to fight back against these pesky pillow invaders, mite-proof dust mite pillow covers are a smart first step.
Dust mites will set up shop in any type of pillow – feather, down, microfiber, or foam. They thrive in the warm, humid environment created by your body heat and nightly drool. It’s enough to make you want to wash your pillowcases daily!
Short of that, experts say you should be washing your pillowcases every single week. And don’t think that keeps things totally clean – even freshly washed pillowcases can have over 170,000% the number of bacteria of a toilet seat after just one week of use. Gross!
2. Fungus Among Us
Dust mites aren’t the only unwelcome guests at the slumber party in your pillow. Pillows are also prime real estate for various types of fungus. Your pillow is basically a petri dish – a moist environment kept at an ideal fungal growth temperature thanks to your body heat.
A study of pillows aged 1.5 to 20 years old found that each one contained a million or more fungal spores. In total, up to 16 different fungus species were identified in the average pillow. Aspergillus fumigatus, a particularly nasty fungus that can cause respiratory illnesses, is one of the most common pillow inhabitants.
The fungi in your pillows literally feed on you. They munch on the dead skin, hair, body oils and sweat that collect on the pillow over time. Experts say people with allergy sensitivities, asthma, or other breathing problems should be especially wary of the fungal festival happening in their pillows.
Throwing your pillows in the wash can help – most pillows are machine washable and should be laundered at least twice a year according to The Sleep Foundation. But even a freshly washed pillow won’t stay fungus-free for long in the face of nightly use. Moisture-wicking pillow protectors can help keep fungal growth in check between washes.
3. Bacterial Breeding Grounds
As if mites and fungus weren’t enough, your pillow is also a major hotspot for bacteria including E. coli and Staphylococcus aureus. One UK study found that a typical pillow may have as much as 350,000 live bacteria colonies per square inch after just one week of use. Yikes!
Like fungus, bacteria thrive on the moist, warm environment and ample food supply that pillows provide. Every time you lay your head down, you deposit a fresh serving of sweat, drool, dead skin and hair for those ravenous bacteria to feast on. Pillowcases should really be changed out every 2-3 days to cut down on bacterial overgrowth. You can also try antibacterial pillow protectors to minimize microbial growth between washings.
While most of the bacteria in pillows are harmless, some can cause issues, especially for those with weakened immune systems. Staphylococcus bacteria from pillows can lead to skin infections if they enter cuts or open wounds. And bacteria like E. coli could theoretically cause illness if they come into contact with your mouth, nose or eyes.
Washing pillowcases frequently in hot water and occasionally washing the pillow itself can help cut down on bacterial buildup. But experts say there’s really no way to completely sterilize pillows without ruining them in the process. That’s part of why they have a limited lifespan for healthy use.
4. Eyelash Mite Invasion
Pillows don’t just attract the usual household bugs – they can also be magnets for face mites. Demodex folliculorum, aka the eyelash mite, is a microscopic bug that lives on the hair follicles of your face, usually around the eyelashes, feasting on dead skin cells and oils. Ugh!
While these mites are generally harmless, they can multiply out of control, causing skin issues like rosacea and blepharitis (eyelid inflammation). And if you have a surplus of them on your face, they’re bound to transfer and take up residence in your pillow when you sleep.
Eyelash mites are extremely common – studies have found them on 100% of people over 60 and 70% of young adults. Getting rid of them completely is next to impossible. But frequently washing your pillowcases in hot water can help keep their numbers down and prevent your pillow from becoming a Demodex breeding ground.
Using hypoallergenic silk or satin pillowcases instead of cotton ones can also create a less cozy environment for eyelash mites to proliferate, as they have a harder time clinging to and burrowing into the smooth fabric. Washing your face before bed is also key to avoid transferring more Demodex to your pillow every night.
5. The Drool Factor
Drooling in your sleep is pretty common. Whether you know it or not, you probably wake up in a small puddle of your own spit most mornings. While drool itself is relatively harmless, it adds to the moisture level in your pillow, which is like ringing the dinner bell for bacteria, fungus, and dust mites.
The enzymes in saliva actually break down the fabric of your pillow over time, creating even more microscopic crevices for germs and bugs to hide in. Dribble enough and you’re basically marinating your pillow in bacteria broth. Using a waterproof pillow protector is a really good idea if you’re a heavy drooler. Waterproof pillow covers provide a spit-proof barrier between you and your pillow to keep drool from seeping in and getting funky.
Drool stains are not just unsightly – they’re a calling card for microbe growth. So if you’re seeing yellowing or discoloration on your pillow, chances are there’s some icky biological activity happening. Time to toss that drool-soaked cushion!
Even if you’re not a big drooler, your pillow still absorbs moisture from sweat, humidity in the air, and the damp hair you lay on it after showering. All that moisture seeps past the pillowcase and into the pillow itself, creating an ideal environment for things to grow. That’s why you need to wash your actual pillow, not just the case, a few times per year.
6. Odor Buildup
If you’ve slept on the same pillow for years, go ahead and give it a sniff. Does it smell like you and your night sweat? Odor buildup is a telltale sign that your pillow has become a germ-festering petri dish. Those smells indicate bacterial activity – and a pillow that’s past its prime.
People shed around a gram and a half of skin per day, much of which ends up in your pillow as you sleep. So after a few years, your pillow filling is literally part you. That’s what dust mites are munching on, and decaying skin cells are what produce that unmistakable old pillow stench. Ick!
Washing your pillow can help reduce odor in the short term. But a smelly pillow is really a red flag that it’s time for a replacement. Pillows that are lumpy, flattened, stained, or yellowed are also past their prime. Expect to swap out cheap pillows after about 6 months, or higher quality ones every 2-3 years.
Dust mite-proof pillow covers, made of tightly woven fabric, are your first line of defense against invasive pillow germs and allergens. Using a protective cover and washing it weekly in hot water can drastically cut down on the skin cells, sweat and drool available for microbes to feed on. Cooling bamboo pillow covers can also reduce moisture and odor buildup.
7. The Lifespan of a Pillow
With normal use and care, most quality pillows will last around 2-3 years before needing to be retired. But even with religious washing, the very best pillows have a finite lifespan. It’s pretty much impossible to keep germs and allergens from eventually taking over, no matter how clean you are.
Cheap polyester-fill pillows need to be tossed even sooner – after around 6 months to a year. Down pillows are the longest-lasting, sometimes enduring up to 5 or 10 years if you’re meticulous about their upkeep. Latex and memory foam pillows fall somewhere in the middle, needing replacement after 2-4 years on average.
Knowing when it’s time to throw in the towel on an old pillow is important. Waking up with neck pain, headaches, allergy flare-ups or worsened asthma are all signs it’s time to move on. Same goes for obvious soiling, permanent odors, lumps or flattening that no amount of fluffing can fix. An old, unsupportive pillow isn’t just gross – it can wreak havoc on your sleep quality.
Instead of waiting until your pillows are visibly past their prime, mark your calendar and replace them every 1-2 years no matter what. Your neck (and sinuses) will thank you for keeping a fresh, clean, supportive place to lay your head. Go ahead and splurge on high-quality pillows – they’re one of the best investments you can make in your health and comfort.
So what’s the bottom line? No matter how clean you are, your pillows are probably way more of a germ magnet than you think. But don’t let the thought of dust mites disrupt your beauty sleep. Using pillow protectors, washing linens frequently in hot water, and replacing pillows every couple years can go a long way towards keeping the microbe party in your bedding under control. Now, rest your weary head and sleep tight – don’t let the literal bed bugs bite!
