Swollen gums are almost always a sign of inflammation, and the most common trigger is bacterial plaque building up along the gumline. About 42% of U.S. adults aged 30 and older have some form of periodontal disease, so if your gums look puffy or feel tender, you’re far from alone. The cause can range from something as simple as skipping flossing for a few days to a medication side effect or a hormonal shift.
Plaque Buildup and Gingivitis
The single most common reason gums swell is plaque, the sticky film of bacteria that forms on teeth every day. When plaque sits undisturbed along the gumline, it triggers an inflammatory response in the surrounding tissue. This process moves fast: within four to five days of plaque accumulating, your body ramps up its defenses. White blood cells flood the area, fluid builds up in the tissue, and collagen in the gums starts to break down. The result is gums that look puffy, bleed when you brush, and may feel sore to the touch.
This early stage is gingivitis, and it’s reversible. Symptoms include bright red or dark red gums, tenderness, easy bleeding during brushing or flossing, and persistent bad breath. Left alone, gingivitis can progress to periodontitis, where the inflammation spreads deeper and begins to damage the bone supporting your teeth. At that point, the swelling becomes harder to reverse without professional treatment.
Crooked teeth, poorly fitting dental work like old fillings or bridges, and dental implants that are hard to clean around all create spots where plaque accumulates more easily. If your swelling seems concentrated around a specific tooth or restoration, that’s a clue.
Medications That Cause Gum Overgrowth
Certain prescription drugs cause the gum tissue itself to grow and thicken, a condition called gingival overgrowth. Three major drug categories are responsible.
- Anti-seizure medications: Phenytoin is the most well-known offender, but other anticonvulsants including carbamazepine and valproic acid have also been linked to gum overgrowth.
- Blood pressure medications (calcium channel blockers): Nifedipine carries the strongest association, though amlodipine, diltiazem, verapamil, and felodipine have all been reported to cause it.
- Immunosuppressants: Cyclosporine, widely used after organ transplants and for autoimmune conditions, has been associated with gum overgrowth since it was first introduced in 1978.
If you started one of these medications and noticed your gums gradually becoming thicker or growing over parts of your teeth, the drug is a likely contributor. The overgrowth tends to worsen when plaque is also present, so meticulous oral hygiene can help limit how severe it gets. Switching to a different medication sometimes resolves the problem, but that’s a conversation to have with your prescriber.
Hormonal Changes, Especially Pregnancy
Hormones can make gum tissue dramatically more reactive to the same amount of plaque that previously caused no problems. Pregnancy is the classic example. Rising levels of estrogen and progesterone increase blood flow to the gums, making them more prone to inflammation, soreness, and bleeding. Pregnancy gingivitis is common enough that many women notice swollen, tender gums starting in the second trimester even if their brushing habits haven’t changed.
Puberty, menstruation, and menopause can produce similar effects on a smaller scale. Hormonal birth control may also contribute. In all these cases, the hormones don’t directly damage the gums. They amplify the body’s inflammatory response to bacteria that are already there, which is why consistent brushing and flossing become even more important during these periods.
Diabetes and Blood Sugar
Diabetes and gum disease have a two-way relationship. High blood sugar increases the production of harmful molecules called reactive oxygen species, which ramp up oxidative stress throughout the body, including in gum tissue. This accelerates the destruction of periodontal tissue and weakens the body’s ability to fight off the bacteria causing the infection. At the same time, the chronic low-grade inflammation from gum disease can make blood sugar harder to control, creating a cycle where each condition feeds the other.
If you have diabetes and notice persistent gum swelling, it may be a sign that your blood sugar management needs attention alongside your oral care. People with poorly controlled diabetes are significantly more susceptible to severe forms of periodontal disease.
Infections and Abscesses
Sometimes gum swelling is localized and intense, centered on one spot rather than spread across the gumline. This pattern often points to an abscess, a pocket of bacterial infection trapped in the gum tissue or around a tooth root. Abscesses cause pain and swelling that can come on quickly and worsen over hours or days.
A more aggressive form of gum infection, called acute necrotizing ulcerative gingivitis, causes rapid-onset swelling, pain, and tissue destruction. It’s driven by specific bacteria and is more common in people who are stressed, malnourished, or immunocompromised. Unlike typical gingivitis, it’s painful from the start and requires prompt dental care.
Any gum swelling accompanied by fever, swelling that spreads to the face or neck, or difficulty swallowing or breathing is a dental emergency. Spreading soft tissue infections can compromise your airway and need immediate treatment.
Brushing Too Hard and Physical Irritation
Aggressive brushing with a hard-bristled toothbrush can traumatize gum tissue directly, causing it to become inflamed and swollen. The irony is that people who brush harder often think they’re doing a better job, when they’re actually injuring the tissue they’re trying to protect. Switching to a soft-bristled brush and using gentle, circular strokes rather than a back-and-forth scrubbing motion often resolves this type of swelling within a week or two.
Other physical irritants include food trapped between teeth, a sharp edge on a broken tooth or filling, and new orthodontic appliances. If your swelling started right after a dental procedure or a change in your oral care routine, mechanical irritation is a likely cause.
Relieving Swollen Gums at Home
For mild swelling without signs of serious infection, a few approaches can reduce inflammation while you address the underlying cause. A saltwater rinse, made by dissolving half a teaspoon of salt in a cup of warm water, helps draw fluid out of swollen tissue and creates an environment less hospitable to bacteria. Swish for 30 seconds and spit. You can repeat this two to three times a day.
Gentle but thorough brushing and daily flossing remain the most effective way to remove plaque and let the gums heal. If your gums bleed when you floss, that’s a sign of inflammation, not a reason to stop. The bleeding typically decreases within a week or two of consistent flossing as the tissue heals. A cold compress held against the outside of the cheek can help with pain and swelling in the short term.
Swelling that persists for more than two weeks, keeps getting worse, or is accompanied by pus, loose teeth, or significant pain points to something that home care alone won’t fix. Those situations call for a dental evaluation to identify whether you’re dealing with advancing gum disease, an abscess, or a medication-related issue that needs a different approach.