How Often Should You Change Your Pillowcase?

man changing pillowcase — A study found the average American changed their pillowcase every 25 days. Grace Cary/Getty Images

Most people spend a huge amount of face time with their pillowcases, quite literally for those stomach-sleepers out there. Despite this, the all-important bed linen doesn't get washed nearly as often as it should be to keep it hygienic. A Mattress Advisor survey found that American men went 29 days and American women 20.4 days before changing their pillowcases. That makes an average of 24.6 days between pillowcase changes, accounting for both sexes.

The case for changing pillowcases more frequently is pretty compelling. The average human spends somewhere between 49 and 60 (or more!) hours per week nestled up to their pillowcase. During this time, we transfer a whole bunch of nasty stuff from our face, body and head to the case, including sweat, body oils and dead skin cells. Exposure to these things can cause everything from skin breakouts/acne to exacerbated allergy or asthma symptoms.

Couple that with the fact that microscopic dust mites (not to mention their fecal matter and itty-bitty dead bodies) multiply rapidly in such settings, and it's easy to see why the pillowcase needs more regular changing. Failure to get rid of the little buggers can cause allergic reactions, including skin problems and even rashes. People with asthma can suffer serious attacks due to constant exposure to dust mites, while others with milder allergies could wind up contending with a chronic runny nose, sneezing or watery eyes.

Change Your Pillowcase Once Per Week — At Least

The best rule of thumb is to change the pillowcase (and the rest of your sheets, while you're at it), at least once a week, according to the National Sleep Foundation. This should be sufficient to ward off dust mites and prevent excessive buildup of other bodily byproducts. However, if you're a really sweaty person, suffer from severe allergies (pollen can build up during allergy season) or sleep with pets, it's probably wise to change the pillowcase every three or four days.

How to Wash Your Pillowcase

The way you wash your pillowcase is just as important as how often you do it.. Most sheets come with washing instructions, so follow those for best results. Ideally, wash the pillowcase in hot water that reaches at least 120 degrees Fahrenheit (49 degrees Celsius), if the fabric type supports it. Anyone with sensitive skin or allergies should use a scent-free, gentle detergent option to prevent unwanted flare-ups. Then, either hang the pillowcase out to dry, or tumble dry in the dryer on low heat.