Home › Dental Services › Bump on Gums

Finding a new lump in your mouth is unsettling, and it is natural to search for answers first. This guide, written by the team at Eglinton Oak Dental, 3960 Eglinton Avenue West, Unit 12, Mississauga, explains the common causes of a bump on the gums, what each type usually looks and feels like, which ones can wait and which ones cannot, and how a dentist diagnoses and treats them. It is general information, not a diagnosis — only an examination can tell you for certain what a bump is.

What is a bump on the gums?

“Bump on the gums” is not a diagnosis — it describes a symptom that many different conditions share. The gum (gingiva) is thin, soft tissue sitting directly over bone and tooth roots, so anything happening underneath — an infection at the tip of a root, a blocked gland, an erupting tooth, extra bone — tends to show up as a raised area on the surface. The useful questions are:

• Is it soft or hard? Soft, squashy bumps are usually fluid or tissue; rock-hard bumps are usually bone.
• Does it hurt? Pain points toward infection or inflammation; painless bumps can still matter.
• What colour is it? Red, white, yellow, clear-blue or the same pink as the gum all suggest different causes.
• Is it next to a particular tooth? Bumps sitting over one root are very often linked to that tooth.
• How long has it been there? Anything present for more than two weeks needs a professional look.

Causes

11 common causes of a bump on the gums

1. Gum or tooth abscess (“gum boil”)

The single most common reason for a new, sore bump on the gum. Bacteria reach the nerve of a tooth through deep decay, a crack or an old large filling, or collect in a deep gum pocket, and pus builds up. The body tries to drain it through the gum, producing a pimple-like bump — dentists call the drainage channel a sinus tract or fistula. It may be red or yellow-white, throb, leak a salty or foul taste, and shrink after it drains — only to come back. An abscess does not heal on its own even when the pain eases, because the source is still inside the tooth or pocket. Treatment is usually drainage plus root canal treatment or, if the tooth cannot be saved, an extraction. Facial swelling, fever or difficulty swallowing makes it an emergency.

2. Canker sore (aphthous ulcer)

A small, round, white or yellow sore with a red border, often at the base of the gum where it meets the cheek or lip. They sting — especially with spicy or acidic food — and are often triggered by stress, minor injury (a toothbrush slip, sharp food), certain toothpastes or hormonal changes. They are not contagious and most heal within 7–14 days. One that is unusually large, keeps recurring or lasts longer than two weeks should be checked.

3. Gum disease (gingivitis and periodontitis)

Plaque and tartar at the gumline cause the gum to become red, puffy and prone to bleeding. In some people the swelling forms a distinct lump between two teeth. As gum disease progresses into periodontitis, deep pockets can trap bacteria and form a periodontal abscess — a tender, swollen bump next to a tooth that may feel loose. A professional deep cleaning (scaling and root planing) removes the cause. Our gum disease guide covers the stages in detail.

4. Pericoronitis (wisdom tooth flap infection)

When a wisdom tooth only partly breaks through, a flap of gum sits over it and traps food. The flap becomes a swollen, sore lump at the very back of the mouth, often with a bad taste, pain on swallowing or trouble opening wide. It is extremely common in late teens and twenties. Cleaning under the flap settles an episode, but repeated flare-ups usually mean the tooth should come out.

5. Dental cyst

A fluid-filled sac that forms around the root of a dead tooth or around a tooth that has not erupted. Cysts grow slowly and are often painless until they become infected or large enough to push on nearby teeth. Many are first found on a routine X-ray. Treatment ranges from root canal treatment to minor surgical removal.

6. Oral fibroma

A firm, smooth, gum-coloured lump made of scar-like tissue, usually from repeated irritation — cheek biting, a rough filling edge or a denture rubbing. Fibromas are benign and painless and do not go away by themselves. If one bothers you or keeps getting bitten, it can be removed in a short procedure and sent for analysis to confirm what it is.

7. Mucocele (mucous cyst)

A soft, clear or bluish, fluid-filled bubble, most often on the inner lip but occasionally near the gums, caused by a blocked or damaged salivary gland. They are painless and many burst and heal, but some keep returning and are best removed.

8. Bony growth (torus or exostosis)

A rock-hard, smooth bump that feels like part of the jaw — because it is. Mandibular tori sit on the tongue side of the lower jaw near the premolars; buccal exostoses sit on the cheek side of the upper or lower molars. They grow very slowly over years, are linked to genetics and teeth clenching or grinding, and are harmless. Treatment is only needed if they get ulcerated by food, interfere with a denture, or become very large.

9. Pyogenic granuloma (“pregnancy tumour”)

Despite the alarming name, this is a benign, bright red, soft growth that bleeds easily, usually at the gumline between two teeth. It is triggered by irritation and hormonal changes, which is why it is common in pregnancy. Many shrink after the baby is born; others are removed. Good cleaning during pregnancy lowers the risk.

10. Teething or an erupting tooth

In babies, toddlers and children aged roughly six to twelve, a bluish or pink swelling over the gum is often simply a new tooth on its way (an eruption cyst). It usually resolves once the tooth breaks through. Our kids dentist team is happy to check anything that looks unusual.

11. Oral cancer (rare, but the reason not to ignore a bump)

Most gum bumps are not cancer. But a lump, a white or red patch, or an ulcer that does not heal within two to three weeks, bleeds without reason, feels hard and fixed, or comes with numbness or a loose tooth for no clear reason must be examined promptly. Risk is higher with tobacco, heavy alcohol use, betel/paan or gutka chewing, and HPV. We carry out an oral cancer screening at every checkup and refer quickly for a biopsy when anything looks suspicious.

Quick Reference

Bump on gums by type: what it probably is

Use this as a rough guide only. Several conditions look alike, which is exactly why an exam matters.

Hard bump on the gums near a molar

A hard bump near a back tooth has three usual explanations. If it is smooth, painless, symmetrical (often on both sides) and has been there for years, it is almost always a bony exostosis or torus — harmless extra bone. If it is tender and appeared recently, it is more likely swelling from an abscess on that molar, which can feel firm before it softens. Behind the last molar in a young adult, a hard lump can be an erupting or impacted wisdom tooth pushing on the gum. A quick X-ray tells these apart in minutes.

White bump on the gums, with or without pain

A painful white bump is usually a canker sore or the pus-filled head of an abscess. The difference: a canker sore is a shallow open ulcer, while an abscess is raised, may leak when pressed, and usually sits over the root of one tooth. A painless white bump can be a fistula from a long-standing, “silent” tooth infection — common under old root-treated or heavily filled teeth — a fibroma, or a white patch (leukoplakia) that should be assessed. Please do not pop or squeeze a white bump; it can push infection deeper.

When to see a dentist about a bump on your gums

• Same day: any of the warning signs in the red box above.
• Within 1–3 days: a painful bump, a bump that drains or tastes bad, or one next to a tooth that hurts to bite on.
• Within 2 weeks: any bump, sore or patch that has not clearly improved.
• At your next checkup: a long-standing, painless, hard bump that has not changed.

If you are not sure which group you are in, call us and describe it — our front desk will tell you honestly how soon you should come in.

Diagnosis & Treatment

How we diagnose and treat a bump on the gums

Investment

How much does it cost to treat a bump on the gums in Mississauga?

The cost depends entirely on the cause. The exam and X-ray are the first step; many bumps need nothing more than reassurance or a cleaning.

These are typical ranges, not quotes — your exact fee is confirmed before treatment starts. Most private plans cover exams, X-rays and cleanings, and a large share of root canal and gum treatment. Eligible patients may be covered under the Canadian Dental Care Plan (CDCP), and we can help you check. See all prices in our Mississauga dental cost guide.

What you can safely do at home until your appointment

• Rinse with warm salt water (half a teaspoon of salt in a cup of warm water) two or three times a day.
• Keep brushing and flossing gently around the area — plaque makes most gum problems worse.
• Use over-the-counter pain relief as directed on the package if you need it.
• Avoid very hot, spicy, acidic or crunchy food on that side.
• Do not pop, squeeze, cut or put aspirin directly on the bump, and do not rely on leftover antibiotics.

Home care can make you more comfortable, but it cannot clear an infection inside a tooth or remove a growth. If the bump is still there after a few days, book an exam.

How to prevent bumps on your gums

• Brush twice a day with a soft brush and fluoride toothpaste, and clean between your teeth daily.
• Have checkups and professional cleanings every six months, or more often if you have gum disease.
• Get cavities and cracked teeth treated early, before bacteria reach the nerve.
• Replace old, rough or broken fillings and ask about a night guard if you clench or grind.
• Stop smoking, vaping and chewing tobacco, paan or gutka — the biggest avoidable risk for gum disease and oral cancer.
• Keep sugary drinks and snacks to mealtimes and stay hydrated to protect against dry mouth.

Frequently asked questions about bumps on the gums

Why is there a bump on my gums?

The most common causes are a gum or tooth abscess (gum boil), a canker sore, swollen tissue from gum disease, an infected wisdom tooth flap, or a harmless bony growth called a torus. Less often it is a cyst, fibroma, mucocele or, rarely, oral cancer. A dental exam and X-ray identify the cause.

Should I be worried about a bump on my gums?

Most gum bumps are not serious, but you should see a dentist if the bump is painful, drains pus or a bad taste, comes with swelling or fever, bleeds easily, or has not gone away within two weeks.

Can a bump on my gums go away on its own?

Canker sores and minor irritation usually heal in one to two weeks. An abscess or gum boil may drain and shrink, but it does not truly heal because the infection is still inside the tooth or gum pocket, so it usually returns until the source is treated.

What is the hard bump on my gums near a molar?

A smooth, painless, hard bump that has been there a long time is usually a bony growth (torus or exostosis), which is harmless. A tender hard bump that appeared recently is more likely swelling from an abscess, and a hard lump behind the last molar can be an erupting wisdom tooth.

Why do I have a white bump on my gums with no pain?

A painless white bump can be a healing canker sore, a drainage point (fistula) from a long-standing tooth infection, a fibroma, or a white patch that needs assessment. Painless does not always mean harmless, so have it checked if it lasts more than two weeks.

What is the painful bubble on my gums?

A painful, pimple-like bubble on the gum is most often a gum boil caused by a tooth or gum abscess. It should be seen by a dentist within a day or two, and the same day if the swelling is spreading.

Is a bump on my gums a sign of oral cancer?

Rarely. Oral cancer is uncommon, but a lump, patch or ulcer that lasts longer than two to three weeks, bleeds without reason or feels hard and fixed should be examined promptly. Eglinton Oak Dental includes an oral cancer screening in every checkup.

Can I pop a gum boil at home?

No. Squeezing or piercing a gum boil can push infection deeper and does not remove the cause. Rinse with warm salt water and book a dental visit instead.

Can I see a dentist the same day for a gum bump in Mississauga?

Usually yes. Eglinton Oak Dental at 3960 Eglinton Avenue West keeps urgent appointments every day, Monday to Saturday from 10 am to 6 pm. Call 905-607-1112 as early in the day as possible.

Does CDCP or insurance cover treatment for a gum bump?

Most private plans cover the exam and X-ray and a large share of treatment such as cleanings, root canals and extractions. Eligible patients may also be covered by the Canadian Dental Care Plan. Eglinton Oak Dental accepts CDCP and verifies coverage before treatment.