Why do my teeth hurt? 10 common causes of tooth pain and sensitivity


If you’ve felt a sudden jolt of pain when drinking water, or from a spoonful of ice cream, you’re not alone. Tooth sensitivity is one of the most common complaints we hear about.

Even worse, people sometimes don’t consume cold or hot food and drink altogether to avoid this uncomfortable feeling. Imagine having to quit coffee!

It’s important to talk to your dentist about sensitivity, as this can be one of the early warning signs of a more serious issue. The good news is most causes of tooth discomfort can be treated by your dentist.

Your teeth have nerve endings to warn you when something is too hot or too cold. Also, they can react to cracks and decay as well. Underneath the hard enamel exterior of your teeth is the dentin layer. This dentin contains microscopic tubes that communicate with nerve endings in the centre of the tooth. If your enamel is damaged from decay, a crack, or a filling that’s leaking, your nerves will warn you there’s something wrong by sending pain signals.

Let’s look at some of the most common causes of sensitivity and pain:

Gum recession

There are many reasons why the gums recede and expose more of the teeth. Most commonly it’s from aggressive tooth brushing, habitual grinding of the teeth, tooth movement from poor tooth position or a combination of factors. Sometimes teeth moved by braces are prone to recession, too. The recession leaves the root surface of the tooth exposed and because there’s no protective enamel there, it can be sensitive to temperature.

Enamel (dentin) erosion

Erosion is the loss of that strong outer layer of the teeth due to acidity in the mouth. There’s a few reasons why this might happen. Drinking pop (even diet cola) lowers the pH in your mouth. Along with sugary and citrus juices, these are the most common dietary reasons that you’ll see erosion in your mouth. Eroded teeth have rounded edges, and appear yellow. This isn’t staining! It’s the inner dentin layer showing through the enamel. The other reasons you might have erosion are medical conditions such as bulimia or acid reflux. It’s important to get these under control not only for dental reasons, but for your overall health.

Brushing too hard

The two reasons above can be made worse by aggressive tooth brushing. We recommend ultra-soft toothbrush bristles, or an electric toothbrush that warns you if you’re brushing too hard. The toothpaste you use is also important. If you have a whitening toothpaste, it could contain abrasives or hard particles that actually damage your teeth with overuse. Remember, you’re only removing loose plaque and debris with your brush. Leave the polishing and heavy-duty cleaning to your hygienist!

Tooth decay (cavity)

Sensitivity to cold, heat and sweets can also be a sign of an early cavity forming in your tooth. Once the decay has eaten through your enamel, the inner, more-sensitive areas of your teeth are exposed. If you leave this too long, you’re risking serious damage.

Gum infection

Gingivitis, or inflammation of the gums, is a common cause of sensitivity and discomfort. Failure to regularly brush and floss, or waiting too long in between cleanings, can cause your gums to flare up. Left untreated it can lead to more serious problems such as bone loss, infection and even losing teeth.

Cracked tooth

A cracked tooth can be obvious, like pain after accidentally biting a popcorn kernel (ouch!). Other times it can be less noticeable. Cracked teeth are usually sensitive to pressure and biting, with people often avoiding chewing on that side. It’s important to have your dentist check your teeth for cracks regularly to avoid serious damage, especially around old fillings.

Sinus infection

If you have pain and sensitivity in your upper teeth, sometimes biting it might not be your teeth at all. Sinus problems such as allergy and infection can mimic toothaches. The roots in your upper teeth are near your sinuses, and because your nerve endings are in the same area it can be confusing as to where the pain is coming from.

Grinding or clenching jaws

Grinding and clenching is a common problem related to stress or poor sleep. You might wake up with sore muscles in your jaw or pain in the joints. Over time, this can lead to enamel wear which causes sensitivity. People who grind their teeth often have flat teeth, or their front teeth might look shorter and worn.

Sensitivity after dental work

It’s not uncommon after a dental procedure to have some sensitivity. In most cases, this is normal as your tooth is recovering from being worked on and adapting to the repairs that have been made. This could last a couple of weeks.

Teeth-bleaching products

Teeth-whitening products are an easy way to improve the appearance of your smile. Using these products, however, can increase your temperature sensitivity. Whether it’s whitestrips, custom bleaching kits or in-office whitening, sensitivity can be an issue. These issues are usually temporary and cease after you stop using the product.

When to see a dentist

If your teeth have become sensitive when they never were before, make an appointment with your dentist. They might be able to recommend a simple treatment, such as a sensitivity-reducing toothpaste, a night guard or modifying your cleaning and brushing routine at home.
Your dentist can tell if you need a corrective procedure, such as a filling to reduce the pain.

Some symptoms should never be ignored. See your dentist right away, or contact another health professional, if you experience the following:

  • Toothache that lasts for more than 48 hours
  • Throbbing or sharp, aching pain that doesn’t subside
  • Migraine or thunderclap headache that extends to your teeth
  • Fever, swelling or a bump on the gums that seems to coincide with your toothache

So, what does this all mean?

There are many reasons why you might feel a sudden pain in your teeth. If you’ve suddenly developed sensitive teeth seemingly overnight, you should speak with your dentist. While it’s not typically considered a dental emergency, teeth that are causing you pain should be examined by a dentist to rule out some of the more serious causes.