Swollen gums are almost always a sign of inflammation, and the most common cause is a buildup of bacterial plaque along the gumline. More than 42% of American adults over 30 have some form of gum disease, making it one of the most widespread health conditions most people don’t realize they have. The good news is that early-stage gum swelling is completely reversible with the right care.
Plaque Buildup and Gum Disease
The number one reason gums swell is gingivitis, the earliest stage of gum disease. When plaque (a sticky film of bacteria) sits on your teeth too long, it irritates the surrounding gum tissue. Your gums respond by becoming red, puffy, and prone to bleeding when you brush or floss. Gingivitis often causes no pain at all, which is why many people don’t realize anything is wrong until they notice pink in the sink after brushing.
Left untreated, gingivitis can progress to periodontitis. At this stage, gums start pulling away from the teeth and forming pockets that trap more bacteria. You may notice persistent bad breath, gum tenderness, sensitivity to hot or cold, pain when chewing, or teeth that feel slightly loose or shift position. While gingivitis can be fully reversed with improved hygiene and a professional cleaning, periodontitis requires more intensive treatment and carries a real risk of permanent damage and tooth loss.
Hormonal Changes
Pregnancy, puberty, menstruation, and menopause can all trigger gum swelling even if your oral hygiene hasn’t changed. During pregnancy, rising levels of estrogen and progesterone increase blood flow to gum tissue, making it more sensitive to even small amounts of plaque. These hormones also alter how the immune system responds to bacteria in the mouth, which is why “pregnancy gingivitis” affects a large percentage of pregnant women, typically showing up in the second trimester.
The gums have receptors for both estrogen and progesterone, meaning they respond directly to hormonal shifts. Estrogen influences how gum cells grow and turn over, which can change the size and shape of the tissue. If your gums seem to swell at predictable points in your menstrual cycle, this is the likely explanation. The swelling usually resolves on its own once hormone levels stabilize, but keeping up with brushing and flossing prevents it from becoming a bigger problem.
Medications That Cause Gum Overgrowth
Certain prescription drugs can cause the gums to gradually enlarge, sometimes dramatically. Three main classes of medication are responsible:
- Anti-seizure medications, particularly phenytoin, though carbamazepine and valproic acid can also trigger it
- Blood pressure medications in the calcium channel blocker family, such as nifedipine and amlodipine
- Immunosuppressants, especially cyclosporine, used after organ transplants and for certain autoimmune conditions
These drugs are chemically very different from each other but share the ability to stimulate excess gum tissue growth. The overgrowth tends to start between the teeth and can eventually cover portions of the tooth surface. In some cases, switching to a different medication in the same class allows the swelling to regress on its own. If you suspect a medication is behind your gum changes, bring it up with both your doctor and your dentist.
Vitamin C Deficiency
Vitamin C plays a direct role in maintaining your gums. Your body needs it to produce collagen, the protein that gives structure to gum tissue, skin, and blood vessels. When vitamin C levels drop low enough, gums become swollen, spongy, and bleed easily. In severe cases this is called scurvy, which is rare today but not unheard of, particularly in people with very restricted diets, eating disorders, or conditions that impair nutrient absorption.
Even a mild deficiency can contribute to gum problems. If your swelling came on gradually and you eat very little fresh fruit or vegetables, it’s worth considering whether your diet is a factor. Your doctor can check vitamin C levels with a blood test.
Signs of a Dental Abscess
Not all gum swelling is garden-variety inflammation. A dental abscess is a pocket of pus that forms from a bacterial infection, either at the root of a tooth or in the gum tissue itself. The swelling from an abscess tends to be localized to one area rather than spread across the gumline, and it often comes with throbbing pain that may radiate into the jaw, cheek, or neck.
Other signs that point to an abscess rather than simple gingivitis include a tooth that feels loose or raised up slightly, sensitivity to pressure or tapping, swollen lymph nodes in the neck, fever, and a general feeling of being unwell. You may also notice a small, soft bump on the gum (sometimes called a gum boil), which forms where the infection is draining. An abscess will not resolve on its own and needs professional treatment to clear the infection and prevent it from spreading.
Other Common Triggers
A few more everyday causes are worth ruling out. A new toothbrush with overly stiff bristles, aggressive flossing after a long break, or poorly fitting dental appliances like braces, retainers, or dentures can all irritate gum tissue and cause localized swelling. Smoking reduces blood flow to the gums and weakens the immune response, making gum inflammation both more likely and harder to spot because nicotine can mask the redness and bleeding that would otherwise alert you.
Stress also plays a role. It raises levels of the stress hormone cortisol, which suppresses your immune system and makes it harder for your body to fight off the bacteria causing gum inflammation. People under chronic stress are also more likely to skip their oral hygiene routine or grind their teeth at night, both of which compound the problem.
What Helps Swollen Gums Heal
For mild swelling caused by plaque buildup, the fix is straightforward. The American Dental Association recommends brushing twice a day and cleaning between your teeth with floss or another interdental cleaner once a day. This removes the bacterial plaque that collects in the spaces between teeth, which is the area most responsible for gum irritation. Use a fresh strand of floss each time, since reused floss can deposit bacteria back into the mouth.
If you’ve been skipping flossing and just started again, some bleeding and soreness in the first week or two is normal. It typically improves as the inflammation calms down. A saltwater rinse (half a teaspoon of salt in a glass of warm water) can soothe irritated tissue in the meantime.
When home care isn’t enough, or if your gums have been swollen for more than two weeks, a dental professional can do a deeper evaluation. For periodontitis, the standard treatment is scaling and root planing, essentially a deep cleaning done under local anesthesia. Your dentist or hygienist removes plaque and tartar from both above and below the gumline, then smooths the root surfaces so gums can reattach more tightly. After the procedure, teeth may feel slightly loose or sensitive for a short time, but this resolves as the gums heal and tighten back around the teeth. Antibiotics are sometimes used alongside the cleaning to help clear stubborn infections.
The timeline for improvement depends on the cause. Gingivitis-related swelling often starts improving within a few days of consistent brushing and flossing, with full resolution after a professional cleaning. Hormone-related swelling may persist until the underlying hormonal shift passes. Medication-induced overgrowth can take weeks to months to reverse after switching drugs. The key variable across all of these is keeping plaque levels low, since bacteria at the gumline make every other cause of swelling worse.