An abscess tooth is a pocket of pus that forms due to a bacterial infection. The infection can occur due to various reasons, including:

• An untreated dental cavity
• An injury to the tooth
• Prior dental work
• Tooth decay
• Gum disease
• A broken, chipped, or impacted tooth
• Radiotherapy or chemotherapy

Bacteria enter through either a dental cavity or a chip or crack in the tooth and spread all the way down to the root, causing swelling and inflammation at the tip of the root. The infection can also spread to surrounding bone and neighboring teeth. Symptoms of an abscess tooth include:

• Severe, constant, throbbing toothache that can spread to your jawbone, neck, or ear
• Redness inside the mouth, or outside the mouth on the face or jaw
• Sensitivity to hot or cold food and drink in the affected area
• A bad taste in your mouth
• Difficulty opening your mouth and chewing food
• A swollen face or jaw
• A high temperature
• A pimple-like bump on your gum that oozes pus

If left untreated, an abscess tooth can lead to serious, even life-threatening, complications. Dentists will treat a tooth abscess by draining it and getting rid of the infection. They may be able to save your tooth with a root canal treatment, but in some cases, the tooth may need to be pulled. Prompt treatment of dental decay reduces the risk of developing a tooth abscess[[5]](https://www.mountsinai.org/health-library/diseases-conditions/t...