A mattress protector accomplishes four things:

Keeps the mattress clean. Human bodies are pretty gross. We all perspire at night. We all produce oil from our skins. Some of us wear makeup. We all also shed dead skin cells. There are other activities that can produce a “wet spot” on the bed. All of this can soak through your sheets and into the mattress. Once a little gets into your mattress, it’s almost impossible to get it out of your mattress. A mattress protector prevents any of that from getting into the mattress and can be taken off and washed.

Keeps the mattress feeling in “like new” condition for longer. Perspiration (or any moisture, like spilling a drink) will wear down the foams in the mattress, shortening the comfort life. It’s a similar effect to a kitchen sponge after too many uses. Even if only a little moisture gets through, after years of every night use that adds up. You will need to replace your mattress more quickly without the protector.

Helps prevent dust mite allergies from acting up. Dust mite allergies are very common and can lead to issues such as sneezing, runny nose, wheezing, and shortness of breath. Dust mites eat dead skin cells, and there will be dead skin cells in your mattress if you don’t use a protector.

Helps protect the warranty. As I mentioned in my warranty post, a stain will void the warranty. Even if the stain has nothing to do with the warranty issue, it still voids the warranty.

For all those reasons, everybody needs a mattress protector.

A mattress protector is different than a mattress pad. Mattress pads generally add some level of padding to the mattress (hence the name,) and is not generally waterproof. Mattress protectors are thin, won’t change the feel of the mattress, and are waterproof. If you buy the correct mattress, you won’t need any extra padding on the mattress, and you get to use the thin, waterproof mattress protector instead.

There are also mattress toppers, which are even thicker than mattress pads. If you use a foam topper, I’d recommend using the mattress protector over the topper, such that it covers both the topper and the mattress.