A gum abscess typically looks like a small boil or pimple on your gums. It appears as a swollen, raised bump that’s usually darker red than the surrounding gum tissue, sometimes with a whitish or yellowish center where pus has collected just beneath the surface. The bump is often tender to the touch and may feel warm.
What a Gum Abscess Looks Like at Each Stage
Before an abscess fully forms, the area around it usually shows the early signs of gum disease: redness, puffiness, and inflammation along the gumline. At this point, there’s no distinct bump yet, just tissue that looks irritated and may bleed when you brush.
As the infection progresses and pus accumulates, a visible lump develops. This is the classic gum abscess appearance: a round, swollen bump that stands out from the surrounding tissue. The color can range from deep red to a pale yellowish tone, depending on how much pus sits near the surface. Some abscesses stay red and firm, while others develop an obvious white or yellow “head” similar to a skin pimple.
In chronic cases, the abscess may form what’s called a gum boil (or parulis), a soft, reddish bump that sits on the outer side of the gum near the affected tooth. This is actually the endpoint of a drainage tract, meaning the infection has created a small channel through the tissue. A gum boil may periodically drain on its own, releasing a salty or foul-tasting fluid into your mouth, then refill and swell again.
Where It Shows Up on Your Gums
The location of the bump tells you something about what type of abscess you’re dealing with. A gingival abscess sits right at the gum surface near the tooth, often appearing as a small raised bump along the gumline. These tend to form when food particles or a foreign object (like a popcorn kernel hull) gets wedged between the tooth and gum. They’re the most superficial type and stay confined to the outer gum tissue.
A periodontal abscess forms deeper, affecting the structures that support and anchor the tooth, including deeper gum tissue and bone. It often appears lower on the gum, away from the gumline, and the swelling tends to be more diffuse. Because the infection sits in a deeper pocket, the bump may feel firmer and less “pimple-like” than a surface abscess.
A periapical abscess originates at the tip of the tooth root, usually from an infected or dying nerve inside the tooth. The visible bump on the gum may appear higher up, above or below the tooth (depending on whether it’s upper or lower jaw), because the pus works its way through the bone and emerges on the gum surface near the root tip. Back teeth, especially lower molars, are the most common location for dental abscesses overall.
How to Tell It Apart From a Canker Sore
People sometimes confuse a gum abscess with a canker sore, but they look quite different once you know what to check for. A canker sore is a small, shallow ulcer with a white, yellow, or grayish center surrounded by a flat red border. It’s an open sore, not a raised bump, and it doesn’t produce pus.
An abscess, by contrast, is a raised, swollen lump with a pus-filled center. It tends to be localized near a specific tooth rather than appearing randomly on soft tissue like the inside of the cheek or lip. Canker sores are painful but harmless and heal on their own within a week or two. An abscess is an active bacterial infection that won’t resolve without treatment and can worsen over time.
Symptoms Beyond What You Can See
The visual bump is usually the most obvious clue, but a gum abscess comes with other signs that help confirm what you’re looking at. Throbbing or pulsing pain near the bump is common, and the affected tooth may feel sensitive to pressure, temperature, or tapping. You might notice the tooth feels slightly loose or like it’s sitting higher than the teeth around it.
Swollen lymph nodes under the jaw or along the neck are another signal. Many people also notice persistent bad breath or a bad taste in the mouth, especially if the abscess is draining intermittently. The gum tissue around the bump may bleed easily when touched.
Signs the Infection Is Spreading
Most gum abscesses stay localized, but the infection can spread into the jaw, throat, or neck. Swelling that extends beyond the gum into the face or neck is a red flag. Fever combined with facial swelling indicates the infection has moved beyond local tissue. Difficulty swallowing, difficulty breathing, or an inability to fully open your mouth all suggest the infection is involving deeper spaces in the head and neck. These situations require emergency care, not a routine dental appointment.
What Happens at the Dentist
A dentist can usually identify an abscess just by looking at it and pressing gently on the area. The bump often feels soft and fluctuant, meaning it gives slightly under pressure because of the fluid inside. They’ll likely tap on the nearby teeth to check for tenderness, which helps pinpoint whether the infection started in the gum tissue or at the tooth root. An X-ray confirms the diagnosis and shows whether bone loss or a root infection is involved.
Treatment depends on the type and severity. For a gum or periodontal abscess, the dentist drains the pus and cleans the infected pocket. For a periapical abscess, the tooth itself needs treatment, typically a root canal or extraction. In either case, draining the abscess usually brings rapid pain relief. Antibiotics may be prescribed if the infection has spread beyond the immediate area, but drainage is the primary treatment since antibiotics alone can’t clear a walled-off pocket of pus.
Left untreated, a gum abscess doesn’t just go away. Even if it drains on its own and the pain temporarily improves, the underlying infection remains and can progressively damage the bone that holds your teeth in place.