A swollen gum usually means your body is fighting irritation or infection in that area. The cause can be as simple as a popcorn hull wedged under your gumline or as serious as an advancing infection. Nearly half of adults over 30 have some form of gum disease, so if your gum is puffy, tender, or bleeding, you’re far from alone.
The Most Common Cause: Plaque Buildup
The most likely reason your gum is swollen is gingivitis, the earliest stage of gum disease. When plaque (a sticky film of bacteria) sits along your gumline for too long, your immune system sends extra blood flow to the area to fight it off. That response is what creates the redness, puffiness, and tenderness you’re noticing. You might also see a little blood when you brush or floss.
The good news is that gingivitis is fully reversible. If you start brushing twice a day with a soft-bristled brush and flossing daily, mild swelling often starts improving within 3 to 7 days. Moderate inflammation can take one to three weeks of consistent care to calm down. If the swelling hasn’t improved after two or three weeks of solid oral hygiene, something else is going on and you’ll want a professional evaluation.
Left untreated, gingivitis can progress to periodontitis, a more serious condition where the infection moves below the gumline and starts breaking down the bone that holds your teeth in place. At that point, the damage isn’t reversible with brushing alone. A dentist uses a probe to measure the depth of the pockets between your gums and teeth; deeper pockets and bone loss on X-rays are what distinguish periodontitis from simple gingivitis.
Swelling in One Spot: Physical Irritation
If only one area of your gum is swollen, the cause is often something local. A popcorn kernel, seed, or small piece of food can lodge between your tooth and gum, creating irritation that triggers an inflammatory response. Aggressive brushing, a sharp edge on a filling or crown, or irritation from orthodontic hardware can do the same thing. In these cases, removing the source of irritation (gently flossing out the trapped food, for example) usually lets the swelling resolve within a day or two.
A broken or cracked tooth can also cause localized gum swelling if bacteria enter the tooth and infect the root. This type of infection, called a dental abscess, produces a distinct tender bump on the gum that may feel like a small, fluid-filled blister. Abscesses don’t heal on their own and need professional treatment.
Medications That Cause Gum Swelling
Certain medications cause the gum tissue itself to overgrow, a side effect that can look and feel a lot like gum disease even if your oral hygiene is good. Three drug classes are the most common culprits:
- Seizure medications: About 50% of people taking phenytoin develop noticeable gum overgrowth.
- Immunosuppressants after organ transplant: Roughly 30% of people on cyclosporine experience it, with the rate climbing to 53% in kidney transplant patients on that drug.
- Blood pressure medications (calcium channel blockers): Around 20% of people taking nifedipine see gum changes, and related drugs like amlodipine can have the same effect.
If you started a new medication in the weeks before your gums began swelling, that connection is worth raising with your prescribing doctor. In many cases, switching to a different drug in the same class resolves the problem. Meticulous oral hygiene also reduces the severity of drug-related gum overgrowth.
Hormonal Changes
Pregnancy is one of the most well-known triggers for gum swelling. Rising estrogen levels increase the permeability of blood vessels in gum tissue, letting more fluid accumulate and making gums puffy and prone to bleeding. At the same time, higher progesterone suppresses the local immune cells that normally keep bacterial plaque in check. This combination creates a perfect setup for inflammation, even in women who had healthy gums before pregnancy.
Progesterone also encourages the growth of specific bacteria linked to gum disease. This is why “pregnancy gingivitis” is so common, particularly in the second and third trimesters. The swelling typically resolves after delivery as hormone levels return to normal, but keeping up with brushing, flossing, and dental cleanings during pregnancy helps prevent it from progressing to something more serious.
Puberty and menopause can trigger similar changes in gum sensitivity, though the effect is usually milder than during pregnancy.
Vitamin C Deficiency
Gum swelling, pain, and bleeding are classic oral signs of low vitamin C. Your body needs vitamin C to maintain healthy connective tissue, including the tissue that holds your gums firmly around your teeth. When levels drop low enough, gums become spongy, inflamed, and bleed easily.
Severe deficiency (scurvy) is uncommon in developed countries but not as rare as you might think. A UK survey found that 25% of men and 14% of women in low-income populations had vitamin C levels below the deficiency threshold. People most at risk include those with very limited diets, heavy smokers (smoking depletes vitamin C), and older adults who eat few fruits and vegetables. If your gums are swollen and your diet has been lacking in produce, increasing your intake of citrus fruits, bell peppers, strawberries, or broccoli can make a meaningful difference.
What Professional Treatment Looks Like
If improved brushing and flossing don’t resolve your swelling, a dentist will likely recommend scaling and root planing, often called a “deep cleaning.” This procedure goes further than a routine cleaning. After numbing your gums with local anesthesia, the dentist or hygienist uses hand instruments or ultrasonic tools to remove plaque and hardite tartar both above and below your gumline. They then smooth the root surfaces of your teeth so the gum tissue can reattach more tightly, making it harder for bacteria to accumulate again.
The procedure is usually done in one or two visits, depending on how much of your mouth is affected. Your gums may be sore for a few days afterward, and you might notice them shrinking as the inflammation resolves, which can make your teeth look slightly longer. In some cases, the dentist will also place a local antibiotic around the roots or prescribe an oral antibiotic to clear any remaining infection.
Signs That Need Urgent Attention
Most gum swelling is uncomfortable but not dangerous. A few specific warning signs, however, mean the infection may be spreading beyond your mouth. If you have a fever along with facial swelling, that combination warrants an emergency room visit if you can’t reach your dentist. Difficulty breathing or swallowing is even more urgent, as these symptoms can indicate the infection has spread into your jaw, throat, or neck. A rapidly expanding swelling on one side of your face, especially with a fever, should never be waited out at home.