Although it’s recommended that we change our pillowcases every second day, this isn’t enough to protect your pillows.
As well as an excellent place to rest your head, your pillow could also be home to dust mites, dead skill cells and fungi.
In fact, a 2005 study found a substantial amount of fungi in pillows tested. According to the results, “Four to 16 different species being identified per sample and even higher numbers found in synthetic pillows."
How often should you change your pillows?
How often you change your pillows depends on the type of pillow you have.
"If you have a plain-old, inexpensive polyester pillow, you should be replacing it every six months," Michael Breus, Ph.D., a clinical psychologist and author of the book Good Night told The Greatist. “But if you have a memory foam pillow or any one with structural integrity, it’ll last you anywhere from 18 to 36 months."
The trick to tell if your pillow needs replacing
Not sure when you last replaced your pillows? There’s a simple test you can do before rushing out to buy a new one: The fold test.
“For pillows filled with natural down, fold the pillow in half and then let go. It should at least slowly regain its normal shape,” sleepbetter.org explains. “For synthetic down, the pillow should spring back quickly and with at least a little force. It’s harder to tell with memory foam pillows. Press on the middle with your hand. It should give, but not all the way to the bottom. When you remove your hand, the pillow should return to its normal shape. If your pillow can’t pass these tests, then you might need a new favourite pillow.”
This article originally appeared on Better Homes and Gardens