For years, I washed my sheets whenever I remembered, assuming that if they looked clean, they probably were. Sometimes that meant every week, sometimes longer when life became busy. Then a conversation with a friend made me wonder whether I had been treating my bedding too casually. She told me that sheets collect sweat, skin oils, dust, and other material while we sleep, even when they look perfectly fresh. I started thinking about how much time we spend in bed and how often we actually clean everything that surrounds us.

I decided to investigate instead of following one of the extreme laundry rules I kept seeing online. Some people claimed bedding needed to be washed constantly, while others said there was little reason to worry about it. The more I learned, the more I realized the answer wasn’t as simple as one universal number. My sleeping habits, bedroom environment, pets, allergies, and even the weather could change what made sense. Then I discovered that one particular piece of bedding deserved far more attention than I had been giving it—and it wasn’t the sheets.