What’s the purpose of a pillow? You mean, besides just sheer comfort and bliss? The purpose of a pillow is pretty simple: To keep your head and neck aligned while you sleep.

There are various types of pillow firmness that make it difficult to decide which one is best for you. To help you out, here are four basic guidelines based on your sleep position to get you started:

• If you are a stomach sleeper, you will need a soft, fairly flat pillow, or you may not need any pillow at all.
• If you are a back sleeper, look for a medium-thick pillow.
• Side sleepers will need a thicker, firmer pillow to help support the neck.
• Combo sleepers, the best pillow for you might have softer and firmer sections, or one that’s lower in the center and higher on the sides

Keep in mind, when picking out a pillow, a pillow squeeze can only tell you so much. If you’re able and you’re somewhere buying a pillow where there’s a mattress around, take a second to lay down and test out how it feels before you buy it.

Now that you’ve found the perfect pillow, there are steps you can take to protect them and make them last longer. Bed pillows should be covered with pillow protectors before putting them in your pillow cases. Pillow protectors can protect your pillows from stains, bedbugs, and allergens. A recent introduction of new performance pillows may have a removable cover that can be cleaned periodically.

Depending on cleaning habits and allergies, you may have to replace your pillow as often as every six months to a year, which is why it is important to take care of them. If you are protecting your pillow, you can go as long as every three years. So keep those pillows clean and use your best judgment!

Happy sleeping!