St. Mark's Hospital - April 22, 2019

If you’re getting the recommended amount of sleep each night, you’re spending at least 49 hours in your bed on a weekly basis. It also means things like oil, dirt, sweat and saliva are building up on your sheets—even if they look clean. Over time, invisible pests like bacteria and dust mites can also accumulate on your bedding.

These contaminants may not just be unsettling to think about as you crawl into bed. Sleeping on dirty bedding could have some health consequences, such as skin breakouts, allergy attacks and even fungal infections.

On the flip side, having clean sheets might improve the quality of your sleep. In fact, a whopping 73 percent of people surveyed by the National Sleep Foundation in 2012 said they got better sleep on fresh sheets—and 85 percent reported general sleeping improvements.

Washing your sheets might be a pain (and let's not even talk about that duvet cover) but it’s important. So, how often should you tackle this task?

What could be lurking in your bedding?

People naturally produce a whopping 26 gallons of sweat in bed each year. Sweating creates moisture, making your bed a potentially ideal environment for fungus to grow. And gravity also plays a role: Over time, gravity causes debris to settle into your mattresses and pillows. In fact, one 2005 study found that feather and synthetic pillows more than 20 years old could harbor up to 16 types of fungal species.

Meanwhile, dirt and allergens, including dust mites—the microscopic arthropods that survive off of dead skin—can build up over time and settle into your sheets, pillows and mattress.

The body also naturally sheds 30,000 to 40,000 dead skin cells every day. Many of these old cells can wind up on your bedding, making even Egyptian cotton, percale or satin sheets a breeding ground for bacteria.

Why having clean sheets is important

The buildup of germs, oil, dirt, sweat and allergens on your pillows and bedding can have a major impact on your health. For example:

Asthma and allergy symptoms can pop up

The presence of dust mites in your home (especially the bedding where you sleep) can make symptoms of allergies and asthma much worse. Constant exposure to these contaminants could even lead to allergic rhinitis, a condition that can cause severe sneezing, congestion or severe asthma attacks.

Eczema flare-ups may become more common

If you’re prone to eczema, bacteria from dead skin cells may up the risk of rashes. In extreme cases, the bacteria can also cause folliculitis, a sometimes-painful infection that leads to itchy skin and acne-like breakouts that can occur anywhere on the body except for the palms or soles. In some cases, folliculitis breakouts require over-the-counter medications or prescription antibiotics.

Germs from pets may increase the risk for infections

You may enjoy snuggling with your furry, four-legged friend every night, but think twice before inviting your pet into your bed. Animals can carry fungal organisms and parasites, like ringworm and scabies, which may transfer to your skin and bedding.

How to wash your sheets—and how often

When it comes to the frequency of washing your sheets, there isn’t a steadfast rule. It’s best to wash your sheets and pillowcases once a week.

Keep in mind however, there are a couple of exceptions. Whenever you’re sick or if you sweat a lot during the night, you may need to wash your sheets and pillowcases more often to get rid of extra germs.

When you do wash your sheets and pillowcases, use warm or hot water (always check the fabric care instructions to make sure you can use hot water) to get rid of germs, and tumble dry the bedding on low. If your washer or dryer has a sanitizing setting, that may be a good option, too. Always make sure your bedding is completely dry before storing it away or making your bed, as wet sheets can easily become mildewed.

Don’t forget your mattress, pillows and comforter

Quilts, pillows and mattresses don’t need to be laundered or cleaned as often as your sheets and pillowcases, but these items can also collect germs, allergens and dirt over time.

Wondering how to wash these bigger, bulkier items? Here are some tips:

Wash your duvet covers once a month

You may be relieved to know that you don’t need to wash everything on your bed on a weekly basis, especially your duvet covers. Throw your cover in the wash once per month if you can, and wash it on warm or hot water, then tumble dry on low.  

Don’t forget your pillows and other bedding items

Pillows, comforters and blankets only need to be washed a few times a year. Try using a delicate cycle to preserve their shape and durability and run them through an extra rinse cycle so all of the soap washes out. Thick or heavy blankets and comforters and pillows may need to be fluffed a few times during the drying cycle, so they’re able to dry evenly.

Keep your mattress fresh

Another way to prevent dust from accumulating is by vacuuming your mattress. Aim to give it a quick cleaning every time you wash your pillows and comforters. Vacuum it with the hose adapter on your vacuum, dab any spots with warm soapy water and let it dry before making your bed again.

Consider investing in protective covers

If you’re allergic to things like dust mites, dander or other allergens, protective zippered covers on your mattress and pillows may prevent these allergens from penetrating the fabric of your bedding, helping you sleep better at night. You can try hypoallergenic sheets, too.

This content originally appeared on Sharecare.com.