Swollen gums are almost always a sign of inflammation, and the most common trigger is bacterial buildup along the gumline. Over 42% of U.S. adults age 30 and older have some form of periodontal disease, so if your gums feel puffy, tender, or look redder than usual, you’re far from alone. The cause can range from something as simple as brushing too hard to something that needs professional treatment, like an infection or medication side effect.
Plaque Buildup and Early Gum Disease
The single most likely explanation for swollen gums is gingivitis, the earliest stage of gum disease. When plaque (a sticky film of bacteria) sits along the gumline for too long, the bacteria release toxins that provoke an immune response in your gum tissue. Your body sends inflammatory signals to the area, and cells in the gum tissue swell and eventually rupture, releasing even more inflammatory molecules. This chain reaction is what produces that puffy, tender feeling.
Gingivitis has a few telltale visual signs: redness, puffiness, and a shiny gum surface right where the gum meets the tooth. Your gums may bleed when you brush or floss, but they typically stay at their normal height. The good news is that gingivitis is fully reversible with consistent brushing, flossing, and professional cleanings.
Left untreated, gingivitis can progress to periodontitis, where the infection moves deeper below the gumline and starts destroying the bone that supports your teeth. At that stage, you might notice gum recession, teeth that look longer than they used to, darker red or purplish gum tissue, and visible gaps where gums have pulled away from the teeth. How fast this happens varies widely depending on your oral hygiene, genetics, smoking habits, and overall health. For some people it takes months, for others years.
Hormonal Changes
Pregnancy, puberty, menstruation, and menopause can all make gums more reactive to even small amounts of plaque. During pregnancy, rising progesterone levels dilate the tiny blood vessels in your gums, increase their permeability, and boost the flow of fluid in the gum tissue. Estrogen further changes the surface layer of the gums, making them less resistant to irritation. The combined effect is a more dramatic inflammatory response to plaque that might not have bothered you before.
This is why gums that were previously healthy can suddenly feel swollen and bleed easily during pregnancy, often in the second trimester. Some people even experience slight pain. The swelling typically improves after hormone levels return to normal, but keeping up with dental cleanings during pregnancy helps prevent it from progressing.
Medications That Cause Gum Overgrowth
Certain prescription drugs can cause the gum tissue itself to grow larger, a condition called gingival hyperplasia. Three classes of medications are primarily responsible:
- Blood pressure medications (calcium channel blockers like amlodipine, nifedipine, diltiazem, and verapamil)
- Anti-seizure medications (phenytoin is the most common culprit, but valproic acid and carbamazepine are also linked)
- Immunosuppressants (cyclosporine, often prescribed after organ transplants)
If you started one of these medications and noticed your gums gradually becoming thicker or growing over more of your teeth, the drug is a likely contributor. Don’t stop taking it on your own, but bring it up with your prescribing doctor and your dentist. Meticulous oral hygiene can sometimes keep the overgrowth in check, and in some cases switching to a different medication resolves it.
Brushing Too Hard
Aggressive brushing is a surprisingly common cause of localized gum swelling. If the puffiness is concentrated along your gumline and appears right after brushing, your technique may be the problem. Scrubbing back and forth with a hard-bristled brush injures the delicate gum tissue, causing redness, swelling, and bleeding.
A better approach is to angle your toothbrush at about 45 degrees to the gumline, use only enough pressure to slightly flex the bristles, and make short gentle strokes or small circles over one to two teeth at a time. A soft-bristled brush does the job without the trauma. If you’ve been brushing aggressively for a while, you may also notice enamel wearing down on the outer surfaces of your teeth.
Infections and Abscesses
A localized, painful swelling that seems to appear quickly, especially near one specific tooth, may point to an abscess. A periodontal abscess forms in the gum tissue itself, while a periapical abscess starts inside the tooth’s inner pulp and spreads to the surrounding tissue. Either way, you’re dealing with a pocket of bacterial infection that won’t resolve on its own. You might notice a small pimple-like bump on the gum, a bad taste in your mouth, or throbbing pain that radiates into the jaw.
Other Common Triggers
Food trapped between teeth or under the gumline can create a localized pocket of irritation and swelling. This is especially common around wisdom teeth, where a flap of gum tissue can trap debris. Canker sores on the gums can also mimic swelling. Vitamin deficiencies, particularly vitamin C (which supports connective tissue) and vitamin K (which helps with clotting), can make gum tissue more fragile and prone to inflammation. Smoking reduces blood flow to the gums and masks early warning signs like bleeding, so smokers sometimes don’t notice gum disease until it’s more advanced.
What You Can Do at Home
Mild gum swelling often responds well to a few days of careful oral hygiene. Brush twice a day with a soft-bristled brush, floss gently to remove trapped debris, and rinse with warm salt water. The standard ratio is one teaspoon of salt dissolved in eight ounces of warm water. If your gums are especially tender, start with half a teaspoon for the first day or two. Swish for about 30 seconds and spit. Salt water helps reduce bacteria and draw out excess fluid from inflamed tissue.
Avoid very hot or very cold foods if your gums are sensitive, and steer clear of alcohol-based mouthwashes, which can irritate already inflamed tissue. If the swelling is around one tooth, try threading floss carefully below the gumline to dislodge any trapped food particles.
Signs That Need Prompt Attention
Most gum swelling is not an emergency, but a few situations call for fast action. Severe or sharp pain that intensifies rather than fading over a day or two can signal an abscess. Visible pus or a pimple-like bump on the gum means infection is present. Swelling that begins spreading toward your jaw, neck, or face is serious because it can eventually affect your airway. A fever alongside gum swelling suggests the infection may be moving beyond the mouth. And if pain is making it difficult to eat, talk, or swallow, don’t wait for a scheduled appointment.
For swelling that’s mild but hasn’t improved after a week or two of good home care, a dental visit is still worthwhile. Your dentist can check for pockets of infection, measure gum recession, and determine whether a professional cleaning or deeper treatment is needed.