Scientists have found thousands of times more germs on pillowcases than on a toilet seat.

According to surveys, the average person changes pillowcases once every three weeks, while dermatologists recommend doing this at least twice a week. Otherwise, sleep can cause allergies, skin infections, and skin inflammation. One type of bacteria found on pillowcases is Staphylococcus aureus. It causes skin and soft tissue infections such as boils and deeper lesions.