You aren’t alone in that; at least one in eight people in the U.S. has sensitive teeth, including kids. So why does this happen to so many of us?

To understand how teeth become sensitive, it helps to know a little about the structure of a tooth . The part above the gums is the crown, which is made of three layers. The outermost layer is the tooth enamel, which is the hardest substance in the body. Beneath that is the softer dentin layer, which is a lot like bone. The innermost layer is the pulp, which contains nerves and blood vessels.

The way the nerves in our dental pulp detect what’s going on at the surface is through the thousands of microscopic tubules running through the dentin. However, if the enamel wears too thin, these tubules can become exposed . Then the nerves inside the teeth feel way too much, which can be painful, particularly when eating or drinking anything hot or cold or even sweet or sour.

Root exposure is another major cause of sensitivity. Unlike the crowns of our teeth, the roots don’t have a layer of enamel to protect them ; that job is performed by the gum tissue. Gum recession, sometimes the result of chronic teeth grinding or of overbrushing, leaves the roots exposed and vulnerable. Sensitivity can also be caused by cavities or an injury that chips or fractures a tooth.

There are a few ways you can fight back if you have sensitive teeth, and it starts with switching to a soft-bristled toothbrush if you aren’t already using one . Hard bristles can cause additional damage to the enamel and gum tissue, and soft bristles are more than enough to effectively clean your teeth. Switching to a toothpaste formulated for sensitive teeth can also help, as can cutting down on sugary or acidic foods and drinks (especially soda).

If you’ve been suffering tooth sensitivity in silence, schedule a dental appointment to discover the cause. In addition to the things you can do to reduce sensitivity on your own, there’s a lot the dentist can do, such as applying a fluoride varnish to strengthen your enamel, performing dental restoration, prescribe a desensitizing toothpaste, or recommend a gum graft if needed to cover exposed roots.