Why Pillows Turn Yellow and How to Clean Them

If you find a pillow you love, buy a few more, Roberts recommends. If your favorite one no longer supports your head and neck the way it normally does, you can replace it with the same type this way. Plus, it’s always nice to have extra pillows on hand for overnight guests.
Know when to say goodbye to your pillow.

If your pillow is lumpy and flat, it’s probably time to part ways. The same goes if the pillowcase itself is stained and yellowed. Allergens like dust mites and pet hair can also build up in old pillows, so treat yourself to a new pillow every year or so (or as needed).