Tooth Infection Symptoms: How to Recognize a Dental Abscess

Throbbing or Persistent Pain

Pain from a tooth infection is often described as a constant, throbbing ache that does not go away. It may be localized to one tooth or radiate to the jaw, ear, or temple on the same side. The pain frequently worsens when you lie down because the change in position increases blood pressure to the head. Unlike sensitivity that comes and goes with hot or cold triggers, infection pain tends to be persistent and may wake you at night.

Swelling in the Face, Jaw, or Gums

As the infection produces pus, swelling develops in the surrounding tissue. You may notice a bump on the gums near the affected tooth (sometimes called a gum boil or parulis). In more advanced cases, swelling can spread to the cheek, jaw, or under the eye. The swollen area may feel warm to the touch and may be firm or soft depending on whether the pus is contained or spreading.

Fever and General Illness

A fever indicates that your body is fighting the infection systemically. While not all tooth infections cause fever, a temperature above 100.4 degrees Fahrenheit (38 degrees Celsius) along with dental pain and swelling is a warning sign that the infection may be spreading beyond the tooth. You may also feel generally unwell, fatigued, or have swollen lymph nodes under the jaw or in the neck.

Bad Taste and Pus Drainage

If the abscess ruptures or drains through a small opening in the gum, you may notice a sudden foul or salty taste in your mouth. You might see or feel pus, a thick yellowish fluid, draining from the gum near the tooth. While the rupture often brings temporary pain relief because it reduces pressure, the infection is still present and still requires treatment.

Sensitivity to Heat

While many dental conditions cause sensitivity to cold, an infected tooth is often more sensitive to heat. If drinking warm liquids or breathing warm air triggers sharp pain in a specific tooth, this is a significant warning sign. Sensitivity to heat suggests the nerve inside the tooth is damaged or dying, which is consistent with infection.

Other Signs of a Tooth Infection

• Pain when biting or chewing on the affected tooth
• A tooth that feels slightly loose
• Swollen lymph nodes under the jaw or in the neck
• Persistent bad breath that does not improve with brushing
• Darkening or discoloration of the affected tooth
• A general feeling of being unwell or fatigued

Periapical Abscess

A periapical abscess forms at the tip of the tooth root. It typically results from an untreated cavity that has reached the pulp, allowing bacteria to infect the nerve and blood vessels inside the tooth. The infection then spreads through the root tip into the surrounding bone, creating a pocket of pus. This is the most common type of dental abscess and is treated by an endodontist with root canal treatment or, if the tooth cannot be saved, extraction.

Periodontal Abscess

A periodontal abscess forms in the gum tissue beside the tooth root, usually in a deep pocket caused by gum disease. Bacteria become trapped in the pocket, leading to infection and pus formation. Periodontal abscesses are treated by a periodontist or general dentist through drainage, deep cleaning, and sometimes antibiotics. If gum disease is the underlying cause, ongoing periodontal treatment is needed.

Gingival Abscess

A gingival abscess is a localized infection in the gum tissue that does not involve the tooth root or the deeper periodontal structures. It is often caused by a foreign object (like a popcorn kernel or food fragment) getting lodged under the gum line. Gingival abscesses are generally the least serious type and respond well to drainage and cleaning of the affected area.

Root Canal Treatment

Root canal treatment is the primary way to save a tooth with a periapical abscess. An endodontist removes the infected pulp from inside the tooth, cleans and disinfects the canal system, and seals it to prevent reinfection. The tooth is then restored with a crown. Root canal treatment has a high success rate and allows you to keep your natural tooth.

Incision and Drainage

If a significant amount of pus has accumulated, the dentist or endodontist may make a small incision in the swollen area to drain it. This provides rapid relief from pressure and pain. Drainage is often performed alongside other treatments (such as starting a root canal or prescribing antibiotics) rather than as a standalone procedure.

The Role of Antibiotics

Antibiotics are prescribed when the infection shows signs of spreading (fever, facial swelling, swollen lymph nodes) or in patients with weakened immune systems. Common antibiotics for dental infections include amoxicillin, amoxicillin-clavulanate, clindamycin, and metronidazole.

It is important to understand that antibiotics control the infection but do not eliminate it. The bacteria live inside the dead or dying tooth pulp, which has no blood supply for antibiotics to reach. This is why the tooth must be treated with a root canal or extraction. Relying on antibiotics alone leads to recurring infections.

Tooth Extraction

If the tooth is too damaged to save (extensive decay, a severe crack extending below the gum line, or a failed previous root canal), extraction may be necessary. Removing the tooth eliminates the source of infection. After extraction, the missing tooth can be replaced with a dental implant, bridge, or partial denture.