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An abscessed tooth happens when a tooth’s root becomes infected with bacteria and pus builds up around it. It’s also called a periapical abcess.


In some cases, the area around the tooth hurts, but not always. If it does, it’s usually a sharp, throbbing pain, especially when you put pressure on your tooth. It might also spread to your jaw or other parts of your face on the side that’s affected.

You also might:

  • Be sensitive to hot or cold temperatures
  • Have puffy gums
  • Notice a bad-smelling odour when you chew with that tooth

If you have swelling in your face and fever, or you have trouble breathing or swallowing, go to the emergency room. The infection may have spread to other parts of your body.


This kind of infection usually happens if a cavity progresses before it gets filled, or if the tooth is injured. Bacteria can get in through the cavity and spread to the nerve. You are more likely to have these kinds of issues if you don’t brush your teeth at least twice a day and floss once a day, or have a diet that is high in sugar. Sugary foods and drinks help bacteria grow, and that can lead to cavities and other problems.


An abscessed tooth won’t go away on its own. See your dentist right away if you have signs of one. It’s important to treat it because there’s a chance it could spread to your jaw or other parts of your head or neck. This is especially true if your immune system is weak because of a health condition, like HIV or AIDS. Certain medications, including some cancer treatments, can also make it harder for your body to fight off infections.

To find out if you have an abscessed tooth, your dentist probably will:

  • Tap on your teeth. If you have an abscess, it’ll hurt when he touches the affected tooth.
  • Take an X-ray. This can tell your dentist if you have an abscess and if it has spread to other parts of your mouth.
Medical Reference Reviewed by Michael Friedman, DDS on June 17, 2019


Mayo Clinic: Tooth Abscess: “Overview,” “Symptoms and Causes,” “Diagnosis.”

NHS Choices: “Dental Abscess.”