Almost nobody does this, but you're supposed to replace your pillows every 12 to 18 months, partly because they break down, and partly because . . . if you look at them under a microscope, they get SERIOUSLY gross.
Plus, using an old pillow . . . or the wrong KIND of pillow . . . can cause headaches, shoulder and arm numbness, wheezing, snoring, or even a weakened immune system if you don't get enough sleep.

So before you spend a ton of money on a new mattress, make sure your pillow isn't the problem. Here's what you should look for, according to how you sleep.

1. If you sleep on your stomach, you should be using a thin, flat pillow that doesn't have much stuffing. Bigger pillows tend to make you sleep awkwardly on your neck.

If that STILL hurts your neck, and you're thinking of buying a new bed, consider a firm mattress with a thin pillow top, so you can sleep on your stomach WITHOUT a pillow.

2. If you sleep on your back, you should probably be using a soft or medium-firm pillow that fills the space between the bed and your neck. Memory pillows also work well.

3. If you're a side sleeper, look for an over-stuffed pillow that gives you even MORE support under your neck. They also prevent you from sleeping with all your weight on one shoulder.