You should get a new pillow when you feel like you are not getting the support that you need. Also, after a few years, you should def think about replacing a fiber and foam pillow just for hygienic reasons. It is a good idea since both materials do break down after time.
Sometimes, depending on what you have going on in your neck you may need a brand new type of pillow all together. For example you may be used to using a simple flat fiber filled pillow. For years you have done well with that. Over time you notice that you are starting to have neck pain, or waking up with neck pain. Sometimes this is due to a neck injury or bad posture day in and day out (maybe its from texting constantly and looking down). Well, you may want to think about getting a contoured neck pillow vs a flat pillow. You may even need a specialized pillow. For instance if you are suffering with numbness and tingling in your hands in conjunction with neck, think about getting a traction pillow.
Keep in mind if you replace your old pillow with the same version of the new one, there is going to be an adjustment period to using that new pillow. New Fiber= New Support. Your neck might not be ready right away for the new pillow, you might have to break it in.
Further reading:
- The New Pillow vs the Old Pillow. Not Cool.
- Can the arc4life pillow be used by side sleepers?
- How to use the arc4life traction pillow- the dummies guide
- Review #804: A good night of sleep
- Even princesses suffer from neck and back pain