Your bedroom might feel like a cozy, clean sanctuary, but lurking in your pillows, sheets, and other comfort items could be a surprising amount of dirt, bacteria, and allergens. If you’ve been putting off cleaning or replacing certain things — like your comforters or even your mattress — it’s time to rethink your routine. Keeping your sleep space sanitary and fresh isn’t just about comfort; it’s about your health, too.

Still, it’s not always clear what items in your boudoir need a little extra attention. To take out the guesswork, we asked an expert which bedroom essentials you need to clean or replace more often (including when and why).

9 bedroom items to clean or replace

1. Mattress

Tell the truth: When was the last time you cleaned your mattress? Probably, like, never. No judgment here (we’re guilty of it, too).

“People rarely clean their mattresses,” says Kelly Reynolds, PhD, director of the Environment, Exposure Science, and Risk Assessment Center at the University of Arizona. But “mattresses can be home to” a lot of icky things, Reynolds says. That’s because, over time, they accumulate stuff like sweat, dead skin cells, and creepy crawlies like dust mites.

Dust mites aren’t visible to the naked eye (they’re about one-quarter to one-third of a millimeter long, per the Asthma and Allergy Foundation of America), but you can bet they’re in your bed, making a feast of the dead skin flakes you shed each day. In fact, one “Ohio State University study showed that a mattress could contain between 10,000 to 10 million dust mites,” Reynolds says. And they aren’t just gross: Dust mites can also flare up health issues, especially for people with asthma, she says.

Mites are also not the only bugs in your bed. Your mattress might also harbor bad bacteria like Staphylococcus aureus (aka, “staph”), Reynolds says. If you’re healthy, staph won’t usually bother you (other than giving you the heebie-jeebies when you think about it). Sometimes, though, it can make people sick if they have a weakened immune system.

How often to clean or replace: Vacuum your mattress every three to six months and spot-clean any stains immediately. Replace it every seven to 10 years (depending on wear and any noticeable sagging).

2. Pillows

Not to freak you out, but every time you lay your head on the pillow, you’re potentially exposing yourself to some pretty yucky stuff.

“Pillows are prone to collecting sweat, oils from your face and hair, dead skin, and dust mites,” Reynolds says. And after a while, they can turn into a petri dish full of bacteria, viruses, fungi, and other allergens, she says.

How often to clean or replace: Wash pillowcases weekly in hot water and wash pillows every four to six months. If they’re not washable, use protective covers and replace them every one to two years.

3. Sheets

If changing your sheets is low on your to-do list, it’s time to move it up.

“Sheets accumulate sweat, body oils, dead skin cells, saliva, and dust mites,” Reynolds says. Plus, soiled sheets make the perfect breeding ground for bacteria. Some research has found that “dirty sheets could harbor more bacteria than a toilet seat,” she says. Gross.

And if you sleep with your furry friend? Your sheets are probably grubbier. Pets add more hair, dander, bacteria, and fungi to the mix, Reynolds says.

Though it’s unlikely these microscopic bedmates will make you very sick, they can still cause health issues like allergies, breathing problems (if you have asthma), rashes, and eczema, to name a few, according to the Cleveland Clinic.

How often to clean or replace: Wash sheets weekly in hot water and/or bleach to kill microbes and dust mites. Replace them every two to three years depending on wear and tear.

4. Comforters and duvets

Washing a comforter or duvet is a hassle. We feel you. No one loves to add more to-dos to their laundry day. Plus, comforters and duvets don’t get as much skin-to skin contact as sheets. So do you really need to wash them that often?

“Comforters and duvets can absorb sweat and dirt over time,” Reynolds says. “They can [also] harbor dust mites and allergens, especially if not covered with a washable duvet cover.” Again, not great news for people with asthma, allergies, or sensitive skin.

How often to clean or replace: Wash duvet covers weekly with your sheets. The comforter or duvet itself should be cleaned every three to six months. Replace every five to 10 years, or sooner if it becomes lumpy or damaged.

5. Humidifiers and dehumidifiers

If you’re using a humidifier or dehumidifier, you’re probably trying to make your air more comfortable—but if you’re not cleaning the machine, you might be making things worse. These machines are breeding grounds for mold and bacteria, which can end up in the air you breathe.

Dirty humidifiers can even spread harmful bacteria like Legionella or mold spores, putting your lungs at risk, Reynolds says. And if you don’t keep them clean, you might find yourself dealing with a flu-like illness called “humidifier fever,” especially if you’ve got pre-existing respiratory issues, she says.

How often to clean or replace: Change or empty the water in your humidifier or dehumidifier daily and use distilled water to avoid scale buildup. Clean your humidifier or dehumidifier once weekly and replace the filters regularly (per the manufacturer’s recommendations).

6. Air purifiers

Air purifiers can do an amazing job at improving indoor air quality (and work wonders for woes like allergies). But only if you’re keeping them clean. “Air purifiers are designed to trap dust, pollen, and allergens, but the filters can become clogged with debris,” Reynolds says. “If left uncleaned, they can be a source of allergens and become breeding grounds for bacteria and mold.”

How often to clean or replace: Clean or replace the filters every three to six months, depending on how often you use the device and the manufacturer’s instructions.

7. Throw or area rugs

Let’s be honest: Most of us would rather do anything but vacuum. And when we finally do it, we just zip over the rug, hoping to be done ASAP. But take this as a friendly PSA to not skimp on cleaning your carpets. “Rugs trap dirt, dust, hair, and allergens,” Reynolds says.

Bacteria, mold, and mites can also thrive on unclean carpets, she says. Your rugs will only hide more critters if you have pets. (BTW, this also goes for throw rugs in your bathroom, along with other bathroom items that accumulate mold.)

How often to clean or replace: Vacuum rugs weekly, and deep clean or steam clean them every six to 12 months.

8. Lampshades

If you’re like most people, cleaning your lampshades is probably not top of mind until they’re covered in dust. “Lampshades collect dust, dirt, and airborne particles,” Reynolds says. “Fabric lampshades, in particular, can harbor allergens and dirt that are not visible to the naked eye.”

How often to clean or replace: Dust lampshades weekly and spot clean stains as needed.

9. Fans

When was the last time you gave your house fans a good scrub? Can’t remember? Yeah, us either. Problem is, “fans accumulate dust, pollen, and airborne debris on their blades,” Reynolds says. When you turn on a ceiling fan or standing fan with blades, it kicks those particles back into the air, worsening the air quality and triggering allergies or asthma, she says.

How often to clean or replace: Dust ceiling or standing fan blades every one to two months.

—medically reviewed by Jennifer Logan, MD, MPH