Swollen Gums Around One Tooth: 7 Possible Causes

Swollen gums are more common than you might think. Most people will experience this at some point, whether it’s due to plaque, gum disease, irritation, or an infection.

Your gums are just as important as any other part of your body. If you notice any changes, it’s important to figure out why so you can fix the problem.

In this article, we’ll look at the different reasons why your gums might swell around one tooth, from the most common causes to the rare ones.

1. Gum Inflammation or Gingivitis

Gingivitis is just a fancy term for "inflammation of the gums." It’s the mildest and earliest stage of gum disease. Studies have reported that it can affect up to 90% of people. This might surprise you because gingivitis can be so mild that it’s easy to overlook.

What causes gingivitis? The main culprit is plaque—a thin, sticky, white film that constantly builds up on our teeth and gums. Bacteria use plaque as a shelter to survive and thrive in the mouth.

When you don’t brush your teeth regularly or neglect oral hygiene, plaque builds up more around your gum line. The bad bacteria then slip into the space between your teeth and gums, triggering inflammation—this is where gingivitis begins.

Healthy gums are firm, pink, and fit snugly around your teeth. But when inflammation kicks in, the tiny blood vessels in your gums thicken to fight off bacteria, leading to swollen gums. They might also become sore, look puffy and shiny, and bleed easily.

Gingivitis usually affects several teeth. If it’s just around one tooth, it often means you’re missing a spot when brushing, typically around one of the back teeth, which are harder to reach and clean with the toothbrush. As a result, these areas are more likely to hold onto plaque and develop inflammation.

Beat Gingivitis Before It’s Too Late

Think of gingivitis as your body’s way of signaling you to take action right away. As we mentioned, it’s the earliest and mildest stage of gum disease. The good news is it’s also easily reversible with some simple improvements to your oral hygiene routine. However, left untreated, it can develop into a more serious and advanced form of gum disease called periodontitis.

To reverse gingivitis:

• Brush your teeth properly for a full 2 minutes, twice a day.


• Make sure to brush every side of your teeth. Missing even a small spot can allow bacteria to build up and cause inflammation.


• Floss once a day, preferably at night before bed, to remove plaque from between your teeth.


• Scrape your tongue daily to reduce the bacteria in your mouth and improve your breath.

2. Gingival Abscess Due to Something Stuck in Your Gums

A swollen gum in one area around your teeth could also be a sign of an abscess.

There are several types of gum abscesses, including gingival, periapical, and periodontal abscesses.

In the case of a gingival abscess, something is stuck in the space between your gum and tooth, usually food. This causes your body to respond with severe inflammation and swelling.

Think about whether you've recently eaten something hard and crunchy, like potato chips or popcorn. It could be a small piece of food that's causing your discomfort. Or it might be something else, like a strand of dental floss or a bristle from your toothbrush.

Common symptoms of a gingival abscess include:

• Isolated swelling that looks like a ball or nodule of varying size on the gum.
• The affected area is smooth, shiny, and red.
• A clear yellow fluid (pus) leaking from the gum line.
• Severe pain that makes it difficult to brush, floss, or eat.

A gingival abscess is not the same as gingivitis. An abscess is a more acute and severe form of infection. The pain is more intense, and there’s fluid (pus) leaking from your gums, which isn’t a symptom of gingivitis.

Treating a gingival abscess primarily involves removing the foreign object from your gum. Once that’s done, the swelling will subside, and your gums will return to their healthy state.

If you’re unable to remove the object by brushing and flossing, it’s important to seek help from your dentist.

3. You May Have a Tooth Infection

Swollen gums caused by an infected tooth are known as a periapical abscess (or simply, a tooth abscess).

The most common cause of this type of abscess is a cavity or tooth decay. When a cavity is left untreated, it can eat away at the tooth and reach its center, where the nerves and blood vessels are located. Bacteria can then continue to spread down into the roots, eventually reaching the bone and gums. At this stage, you’ll notice swelling near the infected tooth, typically at the area around the root tip—this is the periapical abscess.

Common symptoms include:

• Intense toothache or gum pain, especially when pressure is applied or when biting.
• Bad breath and an unpleasant taste in your mouth.
• Swollen gums with pus leakage.
• A sensation that the tooth feels longer than usual.
• A feeling of heat in the affected area.

A dental abscess should never be ignored or postponed. It won’t heal on its own and can worsen over time. Left untreated, it can destroy a significant portion of the jawbone, leading to tooth loss. In the most severe cases, the infection can spread further, posing a serious threat to your overall health.

4. Viral Infection (Oral Herpes)

In addition to bacterial plaque, gingivitis can sometimes result from a viral infection. The most common viral infection in the mouth is oral herpes, caused by the herpes simplex virus type 1 (HSV1).

Nearly 67% of adults under 50 are affected by HSV1. However, most of the time, the virus stays dormant and causes no symptoms. The first outbreak often occurs in childhood, typically through contact with a sore or wound. The virus then spreads and hides in the nerves, where it lies dormant.

Occasionally, the virus reactivates in adulthood, leading to symptoms commonly known as cold sores. Factors that cause the virus to wake up include stress, fever, illness, or sun exposure. While these sores usually appear on the lower lip, they can also develop anywhere in the mouth, including the gums.

If it's the first time you have caught the virus, it can cause an acute condition called herpetic gingivostomatitis. This condition is marked by inflamed, painful, and bleeding gums, often accompanied by fever, fatigue, a burning sensation, and difficulty swallowing.

When gums swell, they look like fluid-filled blisters that break open, leaving painful ulcers.

Mouth sores caused by herpes usually heal on their own within 1-2 weeks. However, to speed up the healing process, your provider may prescribe topical antivirals and numbing gel to relieve discomfort.

5. You May Have Injured Your Gums

Gum injuries often occur during tooth brushing or when you chew something hard. It can also happen if you drink something very hot or use a product that’s too harsh on your mouth.

If you've accidentally hurt your gums, the severity of the injury will depend on how hard you hit them. You might notice redness, swelling, and possibly white patches or ulcers.

Gum injuries caused by trauma typically heal on their own, but it’s important to avoid whatever caused the injury in the first place.

6. Hormonal Changes

Natural hormonal changes during puberty, menstruation, and pregnancy can make your gums more sensitive to plaque and oral bacteria. This increased sensitivity can lead to more severe inflammation and swelling.

Symptoms are similar to regular gingivitis but more pronounced. This means more bleeding, more redness, and more swelling.

7. Swollen Gums and Systemic Diseases (Though Rare)

Swollen gums can sometimes be a sign of systemic diseases, although this is uncommon. General health conditions can manifest in your mouth, particularly your gums, as white or red spots, inflammation, swelling, and ulcerations.

One such condition is lichen planus, an inflammatory disorder affecting about 2% of the population. The exact cause is unknown, but lichen planus is believed to involve an abnormal immune response that damages healthy skin cells and the inner lining of the mouth (mucosa).

Lichen planus lesions can appear on various parts of the body. On the gums, they often look like red, painful areas similar to gingivitis, with possible white patches and ulcerations.

Another rare condition is pemphigus, an autoimmune disorder where the body attacks its own cells. The immune system releases antibodies that destroy the proteins binding cells together. Fluids then leak out, forming fluid-filled blisters that quickly burst and form painful ulcers.

Pemphigus commonly affects the mouth lining and skin. On the gums, it can cause blisters and ulcerations, often accompanied by a sore mouth, bleeding, difficulty eating, and bad breath.