Swollen Gums

What Are Swollen Gums?

Inflammation is the body's protective response to harmful bacteria. When plaque builds up along and below the gumline, the immune system sends white blood cells and fluid to the area to fight the bacterial threat. This influx of blood and inflammatory mediators produces the characteristic gingival erythema (redness), puffiness, and tenderness that patients notice when their gums are swollen.

Gum swelling can be localised — affecting the tissue around one or two teeth — or generalised, affecting the gums throughout the mouth. Localised swelling often points to a specific cause such as trapped food, infection around a single tooth, or irritation from a dental restoration. Generalised gingival enlargement typically indicates a more widespread issue such as plaque-induced gum disease or a systemic factor.

The presentation can also be acute (sudden onset, often painful) or chronic (gradual, persistent swelling that may be relatively comfortable). Acute swelling frequently accompanies infection or trauma, while chronic swelling is more typical of ongoing gingivitis or periodontitis where the inflammatory response has been present for weeks, months, or even years.

Gum swelling matters as a clinical sign because it indicates that the tissues supporting your teeth are under stress. Left unaddressed, the gum disease symptoms associated with persistent inflammation can progress from reversible gingivitis to periodontitis — a more advanced condition involving irreversible bone loss and periodontal pocketing around the teeth.

What Causes Swollen Gums?

Gum swelling has many potential causes. Identifying the correct one is essential for choosing the right treatment approach. Your dental team will work through these possibilities during assessment.

Plaque Build-Up and Gum Disease

Bacterial plaque accumulation along the gumline is the most common cause of swollen gums. Plaque is a soft, sticky film of bacteria that forms on teeth throughout the day. When it is not removed effectively through brushing and interdental cleaning, the bacteria produce toxins that irritate the gum tissue and trigger an inflammatory response.

In the early stage — gingivitis — the gums become red, puffy, and bleed easily when brushed. Gingivitis-related swelling is reversible with professional cleaning and improved home care. However, if plaque is left undisturbed, it mineralises into tartar (calculus), which sits below the gumline and cannot be removed by brushing alone.

Without treatment, gingivitis can progress to periodontitis, where the inflammatory response extends deeper, destroying the bone and connective tissue that support the teeth. Periodontitis symptoms include deepened pockets between teeth and gums, gum recession, tooth mobility, and persistent swelling that does not respond to improved brushing alone.

Gum Infection or Abscess

When gum swelling is focused around one tooth, a localised gum infection or abscess is a likely cause. A periodontal abscess forms when bacteria become trapped in a deep gum pocket, producing pus, pain, and rapid swelling. A periapical abscess originates from infection inside the tooth itself, spreading through the root tip into the surrounding gum tissue.

Both types of abscess can cause significant discomfort, a bad taste from pus drainage, and swelling that may extend into the cheek or jaw. Gum abscess treatment typically requires professional drainage and treatment of the underlying cause to prevent recurrence.

ANUG (Acute Necrotising Ulcerative Gingivitis)

ANUG is a painful gum infection characterised by sudden gum swelling, bleeding, and distinctive crater-like ulcers between the teeth. The condition typically produces a particularly unpleasant taste and noticeable halitosis. ANUG is strongly associated with stress, smoking, poor diet, and compromised immune function.

Unlike straightforward gingivitis, ANUG causes tissue destruction that requires prompt professional treatment. The gum tissue between the teeth (interdental papillae) becomes necrotic, creating the punched-out ulcers that distinguish this condition from other forms of gum inflammation.

Hormonal Changes

Hormonal fluctuations can make gum tissue more sensitive and reactive to bacterial plaque, even when oral hygiene is maintained. Pregnancy gingivitis is particularly common, with hormonal surges during the second and third trimesters increasing blood flow to the gums and amplifying the inflammatory response to plaque bacteria.

Puberty, the menstrual cycle, and menopause can all trigger similar episodes of increased gum sensitivity and swelling. In these situations, the gums may appear disproportionately inflamed relative to the amount of plaque present, because the hormonal environment lowers the threshold for inflammatory response.

Irritation from Dental Appliances

Braces, dentures, retainers, and poorly fitting dental restorations can all irritate gum tissue and create areas where plaque accumulates more easily. Orthodontic brackets and wires make thorough cleaning more challenging, and food debris trapped around components can trigger localised gingival inflammation.

Physical trauma from aggressive brushing technique, using a hard-bristled toothbrush, or overzealous flossing can also injure delicate gum tissue, producing acute swelling and tenderness that may take several days to settle.

Food Trapping

Food debris trapped between teeth, under the gumline, or around restorations with overhanging margins is a common cause of localised swelling. The trapped material promotes bacterial growth and physical irritation of the surrounding gum tissue. This type of swelling often resolves once the debris is removed effectively, but recurring food trapping may indicate a need for adjustment of the restoration or closure of the gap.

Other Causes

• Medication-induced gingival overgrowth — certain medications including phenytoin (anti-epileptic), nifedipine (blood pressure), and cyclosporin (immunosuppressant) can cause gingival hyperplasia, where gum tissue grows excessively around the teeth
• Vitamin C deficiency — although rare in the UK, severe vitamin C deficiency (scurvy) causes gum swelling, bleeding, and tissue breakdown. Milder deficiency may contribute to slower healing and increased inflammation
• Underlying systemic conditions — uncontrolled diabetes increases susceptibility to gum infection and can worsen swelling. In rare cases, unexplained gum enlargement may be associated with blood disorders such as leukaemia
• Smoking — tobacco use impairs blood flow to the gums, weakens the immune response, and accelerates periodontal breakdown. Smokers may experience less obvious bleeding despite significant underlying inflammation

Symptoms That Accompany Gum Swelling

Gum swelling rarely occurs in isolation. Recognising the accompanying signs helps your dental team pinpoint the cause and assess the severity of the condition.

• Bleeding when brushing or flossing — inflamed gum tissue bleeds more easily. Bleeding and swollen gums together are the most common early signs of gingivitis
• Tenderness or soreness — swollen gums are often sensitive to touch, pressure from chewing, or temperature changes in food and drink
• Persistent bad breath — bacteria trapped in swollen gum pockets produce volatile sulphur compounds that cause halitosis, a common accompaniment of gum infection swelling
• Bad taste in mouth — a persistent unpleasant or metallic taste, particularly if pus is draining from an abscess or deep gum pocket
• Gum recession — as chronic inflammation destroys supporting tissue, the gum margin may pull back from the tooth, exposing more root surface alongside the swelling
• Pain when chewing — pressure from biting can intensify discomfort in areas where the gum tissue is inflamed or where an abscess has formed
• Pus or discharge — visible pus between the gum and tooth or draining from a swollen area indicates active infection requiring professional treatment
• Loose teeth — in advanced gum disease, the bone supporting the teeth deteriorates. Tooth mobility alongside swelling is a sign of significant periodontal damage

When Is Gum Swelling an Emergency?

Most gum swelling can be managed with a routine or prompt dental appointment. However, certain signs indicate that urgent same-day care is needed.

• Facial or jaw swelling — when gum swelling extends beyond the mouth into the cheek, jaw, or under the chin, the infection may be spreading into deeper tissue spaces
• Difficulty swallowing or breathing — swelling affecting the floor of the mouth or throat can compromise the airway and requires immediate attention
• Fever or feeling systemically unwell — a raised temperature alongside gum swelling suggests the infection is producing a systemic response
• Rapidly worsening pain — escalating pain that is not controlled by over-the-counter pain relief warrants urgent assessment
• Uncontrolled pus discharge — significant or continuous pus drainage indicates an active abscess that needs professional drainage
• Uncontrolled bleeding after a dental procedure — persistent bleeding with swelling following recent treatment should be assessed by the treating dental team

If you experience any of these symptoms, contact your regular dentist first for an emergency dental appointment. If you cannot reach your dentist, call NHS 111 for guidance on accessing urgent dental care. Attend A&E only for severe facial swelling with airway compromise or difficulty breathing.

Diagnosis and Assessment

A thorough dental examination is the starting point for identifying the cause of gum swelling. Your London dental team will carry out a systematic assessment to determine the underlying problem and plan appropriate treatment.

• Visual examination — assessing tissue colour, shape, texture, and the distribution of swelling to differentiate between localised and generalised causes
• Plaque and tartar assessment — evaluating the amount and location of bacterial deposits along and below the gumline to determine their contribution to the inflammation
• Periodontal probing — measuring pocket depths around each tooth using a calibrated probe. Healthy gums typically measure 1–3mm; deeper pockets indicate periodontal disease
• Bleeding on probing — recording which sites bleed when gently probed, providing an objective measure of active inflammation throughout the mouth
• Localised investigation — checking for trapped food debris, abscess formation, sharp restoration edges, or ill-fitting dental work that may be causing localised irritation
• Medical and medication review — discussing your medical history, current medications, and lifestyle factors that may be contributing to gum tissue hypertrophy or increased susceptibility to inflammation

Swollen Gums Treatment Options

Effective swollen gums treatment depends entirely on the underlying cause identified during assessment. The right approach may be as straightforward as a professional clean or may require more targeted intervention for infection or advanced gum disease. Your general dentistry team will recommend the most appropriate path based on your individual findings.

Professional Hygiene Therapy (Most Common Approach)

For plaque-induced gingival swelling — the most common presentation — professional cleaning by a dental hygienist is the foundation of treatment.

• Scaling and polishing — professional removal of bacterial plaque and hardened tartar deposits that brushing cannot shift, particularly from below the gumline
• Oral hygiene instruction — personalised guidance on brushing technique, appropriate interdental cleaning tools, and product selection tailored to your situation
• Rapid improvement — with professional cleaning and improved home care, gingivitis-related swelling often shows significant improvement within days to two weeks

Deep Cleaning (Scaling and Root Planing)

When assessment reveals periodontitis with pocket formation, deeper cleaning is needed. Scaling and root planing involves cleaning below the gumline under local anaesthesia to remove bacteria, tartar, and toxins from root surfaces within the deepened pockets.

This treatment may require multiple visits depending on the number and depth of affected sites. Following deep cleaning, a structured periodontal maintenance programme of regular review and professional cleaning helps prevent the condition from recurring.

Management of Localised Infection or Abscess

When a gum abscess is present, drainage is typically the first priority. Your dental team will carefully open the abscess to release trapped pus, clean the affected area, and address the underlying cause — whether that is a deep periodontal pocket, trapped debris, or a compromised tooth.

Antibiotics may be prescribed alongside drainage when the infection shows signs of spreading or the patient has systemic symptoms such as fever. However, drainage and treatment of the source remain the primary interventions — antibiotics alone do not resolve gum abscesses.

Antibiotics (When Appropriate)

Antibiotics are not a routine treatment for all gum swelling. They are prescribed when there is evidence of spreading infection, systemic symptoms such as fever, or rapid progression that needs to be controlled. Antibiotics support the immune response and help control systemic involvement, but they do not replace the need for mechanical cleaning and treatment of the underlying dental cause. All antibiotics require a prescription from a qualified clinician.

Adjustment of Dental Restorations

If swelling is related to a poorly fitting crown, filling, or bridge, adjusting, smoothing, or replacing the restoration removes the source of irritation. Overhanging filling margins, rough crown edges, or poorly contoured restorative work can trap plaque and food against the gum, causing persistent localised swelling around one tooth that resolves once the restoration is corrected.

Pain Relief and Home Care Advice

While home measures do not replace professional treatment, they can provide meaningful temporary relief.

• Over-the-counter pain relief — paracetamol or ibuprofen (if medically appropriate) can reduce discomfort and inflammation while awaiting treatment
• Warm salt water rinses — dissolving half a teaspoon of salt in warm water and rinsing gently can help soothe irritated tissue and reduce bacterial load
• Avoid chewing on the affected side — reducing pressure on swollen tissue prevents further irritation and discomfort
• Maintain gentle oral hygiene — continue brushing with a soft toothbrush, even around sore areas, to keep bacterial levels under control
• Cold compress for external swelling — applying a cold pack wrapped in cloth to the outside of the cheek can help reduce facial swelling

Can Swollen Gums Improve on Their Own?

Mild gum irritation from a temporary cause — such as a piece of trapped food, minor trauma from brushing, or eating something sharp — may settle within a few days once the irritant is removed. Improving your brushing technique and incorporating daily interdental cleaning can help mild gingival inflammation improve noticeably.

However, persistent or recurring swelling is unlikely to resolve fully without professional care. Once plaque hardens into tartar below the gumline, no amount of home cleaning can remove it. The tartar continues to harbour bacteria and drive the inflammatory response, meaning the swelling will persist or gradually worsen over time.

Early treatment leads to better outcomes and prevents progression from reversible gingivitis to more advanced periodontal disease. If your gums remain swollen for more than a few days despite improving your oral care routine, professional assessment and cleaning are the most effective next steps.

Prevention of Gum Swelling

Most gum swelling is preventable with consistent oral care habits and regular professional maintenance. These practical strategies reduce your risk significantly.

• Brush twice daily with a soft-bristled toothbrush — angle the bristles at 45 degrees towards the gumline and use gentle circular motions to clean where plaque accumulates most
• Use fluoride toothpaste (1350–1500ppm) — this concentration provides effective protection for both teeth and gums as recommended by UK dental guidance
• Clean between teeth daily — use interdental brushes or floss to remove plaque from areas a toothbrush cannot reach, where gum inflammation often begins
• Spit, don't rinse — after brushing, spit out excess toothpaste without rinsing with water to allow the fluoride to continue protecting your teeth and gums
• Regular hygiene visits — professional cleaning at intervals recommended by your dental team removes tartar build-up before it causes inflammation
• Avoid tobacco — smoking impairs gum healing and masks early warning signs of disease, making prevention and treatment more difficult
• Regular dental check-ups — routine examinations detect early changes in gum health before they progress to significant swelling or disease
• Manage underlying health conditions — keeping diabetes well controlled and discussing medication side effects with your prescribing clinician helps protect gum health
• Balanced diet with reduced sugar — frequent sugar consumption feeds the bacteria that cause plaque and gum inflammation. A balanced diet supports oral tissue health

Swollen Gums in Specific Situations

Swollen Gums in Pregnancy

Pregnancy hormones increase blood flow to the gums and amplify the body's inflammatory response to plaque bacteria. Many pregnant women notice their gums become swollen, tender, and bleed more easily during brushing — even when maintaining the same oral care routine.

Dental treatment, including professional cleaning, is safe during pregnancy and is actively recommended to manage gum health. Your dental team can provide guidance on maintaining gum health throughout each trimester and address any concerns about treatment during pregnancy.

Swollen Gums After Braces

Orthodontic appliances create additional surfaces where plaque can accumulate and make thorough cleaning more challenging. Brackets, wires, and elastics all create niches for bacterial build-up, which increases the risk of gingival inflammation during treatment.

Patients undergoing orthodontic treatment may benefit from more frequent hygiene appointments to keep plaque levels under control. Using interdental brushes designed for braces, orthodontic-specific toothbrushes, and a disciplined cleaning routine all help reduce the risk of swelling during treatment.

Swollen Gums Around One Tooth

When swelling is confined to the gum tissue around a single tooth, the cause is almost always localised — a food trap, a deep periodontal pocket, an abscess, or irritation from a restoration. This pattern requires targeted assessment to identify the specific trigger. Localised swelling should not be assumed to settle on its own, as an underlying infection or structural issue may need treatment to prevent progression.

When to See a London Dentist

While brief, mild gum irritation may resolve with improved oral care, the following situations should prompt you to arrange a professional assessment.

• Swelling lasting more than a few days despite improved oral hygiene
• Worsening discomfort or tenderness that is not easing
• Bleeding that does not settle with gentle, consistent cleaning
• A bad taste or pus around any teeth
• Loose teeth or gum recession alongside swelling
• Visible swelling spreading to face or jaw — seek urgent care

At St Paul's Medical & Dental in the City of London, our experienced team provides thorough gum health assessment and a full range of treatment options — from routine hygiene therapy to advanced periodontal care. Book a consultation to have your swollen gums assessed and receive a clear, personalised treatment plan.

Frequently Asked Questions About Swollen Gums