You’ve no doubt heard about how important finding a comfortable mattress is for clocking quality sleep, but it’s also key to invest in the right pillow. An ill-fitting pillow is not only a sleep thief that keeps you from waking up feeling truly refreshed, but it can also trigger or worsen headaches, neck pain, and arm numbness.

The ideal pillow fit all depends on which type of sleeper you are—though no matter your type, the pillow should keep it’s shape (even when you move), so it should not need to be fluffed often. The goal is to keep your head in “neutral alignment,” meaning that your head is not too far back or too far forward, but rests squarely on your shoulders, similar in position to how you’d look standing up with good posture. Find your type, below, and read on to uncover your perfect pillow fit.

  • If You’re a Back Sleeper: You may benefit from a thinner pillow (so your neck is not thrown too far forward) that has an extra loft in the bottom third to help cradle your neck. (Loft just means how much lift the pillow has, so having extra loft at the bottom means it will be a little thicker in this area.) Memory foam is a good option, because it molds to the shape of your head and neck, as is a water pillow, since it offers all-over consistent support. Also, try sleeping with another pillow under your knees to alleviate pressure on your lower back.
  • If You’re a Stomach Sleeper: You could use the thinnest type of pillow—or even no pillow at all. Sleeping on your stomach puts lots of stress on your lower back, so try sleeping on your side instead and hugging a body pillow if you like the feeling of something pressing against your stomach.
  • If You’re a Side Sleeper: Go for a firm pillow, and one with an extra-wide gusset to help bridge the distance between your ear and shoulder. (Instead of a pillow that has just a top panel sewed directly to a bottom panel, a gusseted pillow has rectangular panels along all four sides that increase its thickness.) You might also sleep with a pillow between your knees to better align your spine.

P.S. Older pillows should be replaced every 18 months or so, because they can be packed with illness and allergy triggers such as mold, dead skin cells, and dust mites. Pillow protectors can help extend the life of your pillow. You can test if a pillow is ‘dead’ by seeing if it springs back after you fold it in half. If it doesn’t spring back, it’s time to get a new one.