Although many people sleep with more than one pillow, the recommended number is just one. A pile of pillows might look attractive and feel comfortable as you lay your head down to rest, but a single pillow is all you need for optimal support and neck alignment. In fact, more pillows usually mean more strain on your neck, shoulders and spine, causing pain and poor posture.
The purpose of using a pillow is to make sure your neck is aligned with your spine. If you are piling the pillows high, making your neck too elevated, the unnecessary strain on your neck and spine will likely cause poor sleep and back pain.
Sleep studies have also found that using only one pillow reduces the amount we toss and turn at night. The higher the number of pillows, the more your sleep takes a hit. So not only does one pillow offer the best support, it helps you to sleep more peacefully overall.