A tooth abscess typically shows up as a swollen, red bump on the gum near the affected tooth, often resembling a pimple filled with yellowish-white pus. Depending on how far the infection has progressed, you might see anything from a small blister on your gumline to noticeable swelling across your jaw or cheek. Here’s what to look for at each stage and what the different types look like.
The Gum Boil: The Most Common Sign
The most recognizable visual sign of a tooth abscess is a small, raised bump on the gum, sometimes called a gum boil. It usually appears near the base of the infected tooth, right where the gum tissue meets the looser tissue of the inner cheek. This bump forms because the infection creates a drainage channel from the tooth root through the bone and out to the gum surface, following the path of least resistance. The result is a soft, rounded spot that can range from the size of a pinhead to a small pea.
The bump is often red or yellowish, depending on how much pus has accumulated beneath the surface. You might notice it looks like a whitehead. In some cases, it ruptures on its own, releasing a foul-tasting, salty fluid into your mouth. When that happens, the pain often decreases temporarily because the pressure has been relieved. But the infection is still there, and the bump will usually refill.
What the Tooth Itself Looks Like
The abscessed tooth may look visibly damaged. You might see a large cavity, a darkened or grayish tooth, or a cracked or broken crown. In some cases the tooth looks completely normal from the outside, with the infection hidden deep at the root tip. One clue is that the tooth may appear slightly raised compared to the teeth around it, as if it’s been pushed upward (or downward, for upper teeth) by the swelling underneath. The surrounding gum tissue is often redder than normal, puffy, and tender to touch.
If the abscess is along the side of the tooth rather than at the root tip, you may notice the gum pulling away from the tooth or looking swollen in the pocket between the tooth and gum. This type of abscess, called a periodontal abscess, can also cause the gum to bleed when you brush or press on it. The tooth itself may feel loose or wobbly.
Two Types, Two Locations
A periapical abscess forms at the very tip of the tooth’s root, usually because decay or a crack has let bacteria reach the inner pulp. The gum boil for this type tends to appear high on the gum, above (or below, for lower teeth) the affected tooth. You’ll often notice sensitivity to hot and cold, pain when you tap on the tooth, and increased looseness.
A periodontal abscess starts in the gum tissue itself, in the pocket between the tooth and gum. The swelling shows up right along the gumline rather than higher up. It looks like a shiny, taut red bulge pressed against the side of the tooth. Bleeding from the area is more common with this type, and you may see pus oozing from the gum pocket when you press on it.
Pus and Drainage
The discharge from a tooth abscess is thick, yellowish or yellowish-green, and has a distinctly unpleasant smell. If the abscess drains into your mouth, you’ll notice a sudden rush of bad-tasting, salty liquid. The odor can also cause persistent bad breath that doesn’t improve with brushing or mouthwash. Some people first notice the taste and smell before they ever see the bump on their gum.
When Swelling Spreads Beyond the Gum
As the infection grows, swelling can move beyond the gumline into the soft tissues of your face. This is where a tooth abscess stops being just a dental problem and becomes a medical one. You might notice your cheek becoming visibly puffy on one side, warmth and redness over the skin of your jaw, or swelling under your chin. The skin in the swollen area may look stretched and shiny.
Facial swelling from a dental abscess is a sign of cellulitis, meaning the infection has spread into the surrounding tissue. In severe cases, the swelling can involve the area around the eye or the front of the neck. If swelling reaches the floor of the mouth, the tongue can become enlarged and pushed upward, making it hard to swallow or breathe. This is a life-threatening condition called Ludwig’s angina, and it can develop quickly. Visible signs include neck swelling, skin discoloration along the jaw and neck, and a protruding tongue.
What It Looks Like in Children
Abscesses in children’s baby teeth look similar to those in adults: red, swollen gums and sometimes a visible bump near the tooth. Because children’s jawbones are thinner and less dense, the swelling can appear more quickly and spread to the jaw or cheek faster. A child with an abscessed tooth may have a noticeably swollen face on one side, red gums that look puffy around a single tooth, and visible discomfort when chewing. Children are less likely to describe the symptoms clearly, so a visible gum boil or facial asymmetry is often the first thing a parent notices.
Signs That Need Immediate Attention
A small gum boil that drains on its own can lull you into thinking the problem is resolving. It isn’t. The infection will persist or worsen without treatment. Certain visual signs indicate the situation is urgent: swelling that extends into the cheek, under the jaw, or around the eye; difficulty opening your mouth or swallowing; a swollen or displaced tongue; and redness or discoloration spreading across the skin of your neck. Fever combined with any facial swelling is another clear signal that the infection is advancing beyond what your body can contain on its own.