Swollen gums are most often caused by plaque buildup along the gumline, which triggers an inflammatory response in the surrounding tissue. It can happen surprisingly fast: plaque reaches its peak accumulation in about four days, and visible gum inflammation can appear by day five if that plaque isn’t removed. But bacterial plaque is only one of many triggers. Hormonal shifts, certain medications, viral infections, and nutritional deficiencies can all cause your gums to swell.
Plaque Buildup and Gum Disease
The most common cause of swollen gums is the accumulation of dental plaque, a sticky film of bacteria that forms constantly on your teeth. When plaque sits undisturbed along the gumline, the bacteria within it release toxins that provoke your immune system. Your body responds by sending extra blood flow and immune cells to the area, which produces the redness, puffiness, and tenderness you recognize as swollen gums. This early stage of gum disease is called gingivitis.
Certain bacteria are especially aggressive. Some species invade the gum tissue directly by hijacking your cells’ internal structure. Others produce toxins specifically designed to destroy white blood cells, weakening your body’s ability to fight back. As the bacterial community shifts from harmless to harmful, the immune response intensifies and can start damaging the gum tissue itself rather than just defending it.
If gingivitis goes untreated, it can progress to periodontitis, a more serious condition where the inflammation spreads deeper and begins breaking down the bone supporting your teeth. Nearly 30% of adults aged 30 to 44 have some form of periodontitis, and that number climbs to roughly 60% in adults 65 and older, according to national survey data from the National Institute of Dental and Craniofacial Research. Most of these cases are mild or moderate, but about 4% of younger adults and 9% of older adults have the severe form.
Hormonal Changes
Pregnancy is one of the best-known hormonal triggers for swollen gums. Rising levels of estrogen and progesterone alter blood vessels in the gum tissue in two important ways. Estrogen increases the permeability of blood vessel walls, allowing fluid to leak into the surrounding tissue and causing visible puffiness. Progesterone, meanwhile, suppresses the local immune response by reducing the effectiveness of the immune cells that normally keep plaque bacteria in check.
This creates a double problem: your gums become physically more prone to swelling while simultaneously losing some of their defense against the bacteria that cause it. Progesterone also encourages the growth of specific anaerobic bacteria linked to gum disease. The result is that gums that were perfectly healthy before pregnancy can become red, tender, and prone to bleeding, a condition sometimes called pregnancy gingivitis. Similar hormonal effects can occur during puberty, menstruation, and menopause, though pregnancy produces the most dramatic changes.
Medications That Cause Gum Overgrowth
Several commonly prescribed medications can cause gum tissue to enlarge independently of plaque or infection. The three main drug classes responsible are anti-seizure medications, immunosuppressants, and blood pressure drugs.
- Anti-seizure medications: Phenytoin, one of the oldest epilepsy drugs, causes gum overgrowth in roughly 50% of people who take it.
- Immunosuppressants: Cyclosporin, used after organ transplants and for autoimmune conditions, causes gum enlargement in 25% to 80% of patients.
- Calcium channel blockers: Blood pressure medications like nifedipine, amlodipine, and felodipine are the most frequent offenders in this class, though other calcium channel blockers can also contribute.
The overgrowth typically starts between the teeth and can eventually cover a significant portion of the tooth surface. It tends to worsen when oral hygiene is poor, because plaque accumulation compounds the drug’s effect on the tissue. If you notice your gums growing over your teeth after starting a new medication, your dentist and prescribing doctor can discuss whether switching to an alternative drug is an option.
Viral and Fungal Infections
Not all gum swelling is caused by the slow buildup of plaque bacteria. Viral infections can produce sudden, intense gum inflammation. Herpes simplex virus type 1 (the same virus responsible for cold sores) causes a condition called herpetic gingivostomatitis, most common in children but possible at any age. It typically starts with a high fever, followed by widespread painful ulcers across the gums, inner cheeks, and palate. The gums become deeply red and swollen, and small yellowish sores (roughly 2 to 5 mm across) appear and bleed easily. These ulcers usually heal without scarring in two to three weeks.
Fungal infections, particularly oral thrush caused by Candida yeast, can also irritate and inflame gum tissue. This is more common in people with weakened immune systems, those taking antibiotics, or denture wearers.
Vitamin C Deficiency
Vitamin C is essential for producing collagen, the structural protein that holds your gum tissue together and keeps blood vessel walls intact. When your body doesn’t get enough vitamin C, those blood vessels become fragile and leak, and the gum tissue loses its structural integrity. The classic oral signs of scurvy (severe vitamin C deficiency) are swollen, spongy gums that bleed spontaneously and are extremely tender to touch. In advanced cases, the gum tissue can develop finger-like overgrowths that extend well beyond their normal boundaries.
Full-blown scurvy is rare in developed countries, but marginal vitamin C deficiency is not. If your gums are persistently swollen and you eat very little fresh fruit or vegetables, low vitamin C could be a contributing factor.
Braces, Dentures, and Dental Work
Anything that sits against your gum tissue for extended periods can cause localized swelling. Orthodontic brackets and bands create surfaces where plaque accumulates more easily, and the brackets themselves can physically irritate the surrounding gums. Excess bonding material around brackets has been linked to increased gum bleeding in nearby areas. Ill-fitting dentures, rough crown margins, and poorly contoured fillings all create similar problems by trapping food and bacteria or rubbing directly against the tissue.
The swelling in these cases tends to be limited to the area around the offending appliance or restoration. Improving oral hygiene around the hardware helps, but if the fit is genuinely poor, the appliance itself may need adjustment.
What You Can Do at Home
For mild gum swelling caused by plaque buildup, consistent brushing and flossing is the most effective first step. Because plaque can produce visible inflammation in as few as five days, even a brief lapse in oral hygiene can trigger swelling, and resuming thorough cleaning can reverse it within a similar timeframe.
A warm saltwater rinse can help reduce inflammation and keep the area clean. The standard ratio is one teaspoon of salt in eight ounces of warm water. If your gums are very tender, start with half a teaspoon. You can rinse several times a day, particularly after meals, but avoid overdoing it since swallowing large amounts of salt water can dehydrate you.
If your gums remain swollen for more than two weeks despite good brushing and flossing habits, that’s a signal something beyond simple plaque is involved. A bump on the gums, severe pain, or swelling that keeps getting worse are also reasons to get a professional evaluation sooner rather than later. Persistent swelling that doesn’t respond to home care can point to medication side effects, hormonal shifts, nutritional issues, or more advanced gum disease that needs targeted treatment.