Abscesses are infected areas surrounding the roots of your teeth. These infected areas can consist of pus-filled sacs surrounding the tooth's root. An abscess can cause you to run a fever, feel ill or tired. You may also have a toothache or pain when eating. Swollen glands in your neck, swelling of the facial muscles on an infected side, and swollen and tender gums can all be signs of an abscess. Abscess can develop for many reasons. However, tooth decay and gum disease are the of primary causes. Severe tooth decay can eventually kill the pulp of the tooth and can continue damage to cause a painful abscess. Gum disease from untreated bacteria between your teeth can also lead to abscesses. Should you have any of the above symptoms or an abscess, don't delay your treatment. The pain of the abscess may decline but the infection will continue to grow and cause further damage to your mouth and gums. Contact your dentist for treatment of your abscess.