Experts advise replacing your pillows every one to two years. Following this recommendation will make sure that you use clean pillows, has good head support, and are allergen-free. It is easy to know when it is time to replace your pillows. If you observe too much yellowing on your pillows and your allergies start acting up are signs that you need to replace them. When your pillows start to have lumps that make sleeping very uncomfortable, it may be time to let your pillows go. Replacing your pillows at the recommended period can prevent sore muscles, allergic reactions, and skin breakouts. Different types of dirt can seep through your pillows like face oils, drool, and sweat, which can cause yellowing and eventually irritate your skin. If your pillow cannot provide proper head and neck support while you sleep, you might wake up feeling sore. It is about time you change your pillow to a new one that can give you better support.