If you ever experience pain or discomfort when eating something that’s too hot or cold, you’re not alone. According to the Journal of the American Dental Association, one in eight people have sensitive teeth.

Tooth sensitivity is more than just a nuisance, though. It can be a sign of tooth damage, infection, and several other dental problems. To protect your oral health, you should try to narrow down the cause of your tooth sensitivity and avoid anything that may make it worse.

You may be surprised by some of the factors that can contribute to tooth sensitivity. Here are seven unexpected causes of sensitive teeth.

1. Diet

Acidic foods can wear away the enamel on your teeth, exposing the sensitive layer of dentin underneath. According to the Academy of General Dentistry, one-third of dentists believe that diet is the biggest cause of sensitive teeth.

Here are some of the most common acidic foods and drinks that can affect your oral health:

1. Fruit juice
2. Sports drinks
3. Tomatoes
4. Berries
5. Citrus fruits
6. Wine

It can be especially harmful to consume these foods and drinks right before you go to bed or while you exercise. Your body doesn’t produce much saliva during these times, so particles from the food can remain on your teeth and continue to wear down your enamel for a prolonged time before being washed away.

Chewing ice is another bad habit that can cause sensitive teeth. The ice may chip your enamel and expose the sensitive inner layer of your tooth. If you bite down on an ice cube at the wrong angle, you could even crack, split, or break your tooth, which will lead to severe pain and sensitivity.

2. Hard Teeth Brushing

Being zealous with your brushing may seem like a good idea, but brushing too hard or too often can actually be harmful. Aggressive brushing, especially when done with a hard-bristled toothbrush, can wear away your enamel and your gums. Brushing too often or for too long can have the same effect.

You don’t have to brush your teeth aggressively to keep them clean. A soft-bristled brush will remove all the plaque and food debris without being too harsh on your teeth, and two minutes of gentle brushing twice per day is enough to clean your mouth. You should hold your toothbrush at a 45-degree angle and brush in a circular pattern instead of scrubbing back and forth vigorously.

3. Using the Wrong Toothpaste

Certain dental products can be more harmful than helpful. For example, some whitening toothpastes contain alcohol and other ingredients that cause tooth sensitivity. Home whitening kits and professional whitening treatments can also cause sensitivity, especially if they use peroxide.

Long-term mouthwash use can affect your tooth enamel as well. Many over-the-counter mouthwashes contain acids, which can wear down the enamel and expose the layer of dentin underneath. If you already have some exposed dentin, the mouthwash can make any existing sensitivity worse.

4. Pregnancy

Sore and sensitive teeth and gums are a common complaint among pregnant women. As your hormones change, your body may react differently to bacteria in the mouth. This can lead to periodontal infection, which causes sensitive teeth and gums. Pregnant women are more likely to develop gum disease than the general population as well, and sore, sensitive, and bleeding gums are some of the most common gum disease symptoms.

Your body also experiences an increase in blood flow when you’re pregnant, which can make your gums swell up and feel sensitive to hot and cold food. You may have food cravings while pregnant, too, and consuming sugary or acidic foods can be harmful to your teeth.

5. Stress

Mental and emotional stress can take a physical toll on your body, so you may find your teeth becoming more sensitive after a stressful life event. When you’re stressed, you may clench and grind your teeth. Many people grind their teeth without realizing it, but the pressure from the clenching can wear away the tooth enamel and lead to pain and sensitivity.

Teeth grinding in your sleep can be an especially serious problem because you have no way of knowing that it’s happening. If you wake up with headaches or jaw pain and have noticed your teeth becoming more sensitive, your dentist may recommend that you wear a night guard while you sleep to protect your dental health.

6. Dental Work

Tooth sensitivity is common during recovery from dental work, especially after the following procedures:

1. Root canal
2. Tooth extraction
3. Crown fitting
4. Filling
5. Dental implant placement

Fortunately, sensitivity after dental work is almost always temporary. You should only feel sensitivity around the tooth that was treated, and it should go away within a few days or weeks of the procedure.

7. Sinus Infection

Sinus infections can cause tooth pain and sensitivity, particularly in the upper rear teeth. The sinuses are located behind the cheek bones, so they’re in close proximity to the upper molars. Because they’re so close together, sinus pain can be mistaken for tooth pain, or the pain may actually spread to the mouth.

You also may be unable to breathe through your nose when you have a sinus infection, and mouth breathing can increase your risk of dental problems by promoting dry mouth. Without enough saliva to keep your mouth clean and clear, the bacteria can accumulate on your teeth and eat away at your enamel.

Tooth sensitivity is often a sign of a bigger dental issue, so it’s not something to ignore. If you’ve noticed your teeth becoming more sensitive, you should visit your dentist to figure out the cause and find the best solution.