Inflamed gums are almost always a response to bacterial buildup along the gumline, a condition called gingivitis that affects over 42% of American adults over age 30. The good news: if caught early, gum inflammation is reversible, often within days to weeks of better oral care. But bacteria aren’t the only culprit. Hormones, medications, nutritional gaps, and even brushing too hard can all make your gums red, swollen, or tender.
How Bacteria Trigger Gum Inflammation
Your mouth is home to hundreds of bacterial species, most of them harmless. Problems start when plaque, a sticky film of bacteria, builds up along and beneath the gumline. In a healthy mouth, certain mobile bacterial species exist at very low levels. When oral hygiene slips, those species multiply and shift the balance of the microbial community.
What happens next is surprising. Rather than immune cells sounding the alarm first, it’s the gum tissue cells themselves that detect the shift. These epithelial cells, the outermost layer of your gums, recognize components of the harmful bacteria and respond by producing an inflammatory signal called IL-23. A small amount of inflammation is protective, helping your body fight off invaders. But IL-23 flips that response from helpful to destructive. As NIDCR researcher Niki Moutsopoulos has described it, once IL-23 gets involved, inflammation switches from protective to pathogenic. That’s when you notice redness, swelling, tenderness, and bleeding when you brush or floss.
Left unchecked, this chronic inflammation can progress from gingivitis to periodontitis, where the tissue and bone supporting your teeth begin to break down. Periodontitis affects nearly 60% of adults 65 and older, up from about 30% in the 30-to-44 age group. The progression isn’t inevitable, though. Gingivitis is the only stage that’s fully reversible.
Other Common Causes
Brushing Too Hard
Aggressive brushing doesn’t clean your teeth better. It damages your gums. Scrubbing with a hard-bristled brush or pressing too firmly can wear away delicate gum tissue, causing redness, soreness, and recession over time. Damaged gums are also more vulnerable to infection, which can make the problem worse. Soft-bristled toothbrushes are the standard recommendation because they clean effectively without irritating tissue. Improper flossing, snapping the floss into gums rather than gently curving it along each tooth, causes similar trauma.
Hormonal Changes
Pregnancy is one of the most well-known triggers. Shifts in estrogen and progesterone alter how gum tissue responds to bacteria, making it more prone to swelling and bleeding even with normal plaque levels. The gum tissue itself undergoes structural changes during pregnancy: the outer protective layer thins, and the underlying tissue becomes more inflamed. This is common enough to have its own name, pregnancy gingivitis, and it typically resolves after delivery. Puberty, menstruation, and menopause can cause similar fluctuations in gum sensitivity.
Medications
Certain medications cause gum tissue to physically overgrow, a condition called gingival hyperplasia. Three drug classes are the primary offenders. Anticonvulsants used for seizure disorders (phenytoin is the most recognized) are a common cause. Calcium channel blockers prescribed for high blood pressure, particularly nifedipine, can also trigger overgrowth. The third category is cyclosporine, an immunosuppressant used after organ transplants and for autoimmune conditions. If you take any of these and notice your gums growing over your teeth or becoming unusually puffy, bring it up with your prescriber. Switching medications or adjusting your dental care routine can help.
Vitamin C Deficiency
Severe vitamin C deficiency leads to scurvy, and swollen, bleeding gums are one of the hallmark symptoms. Your body needs vitamin C to maintain connective tissue, including the tissue that holds your gums firm against your teeth. You don’t need to be dramatically deficient to notice effects. The daily amount needed to prevent problems is modest: 75 to 90 milligrams, roughly the amount in a single orange. People with very restrictive diets, certain digestive conditions, or heavy alcohol use are most at risk.
When Inflammation Becomes an Emergency
General gum inflammation is uncomfortable but not urgent. A periodontal abscess is different. An abscess forms when infection gets trapped in a pocket between your tooth and gum, creating a painful, pus-filled bump. It looks like a boil or pimple on your gums, usually darker than the surrounding tissue, and the swelling can range from mild to severe.
Beyond the visible bump, abscess symptoms can include a persistent toothache, sensitivity to hot or cold, bad breath, a foul taste, swollen lymph nodes in your neck or jaw, and a loose tooth. Some people experience pain; others don’t, which makes the visual appearance important. A periodontal abscess is a dental emergency. If you develop a fever, chills, nausea, difficulty breathing, or difficulty swallowing alongside gum swelling, those are signs the infection may be spreading and you need emergency care.
How Quickly Inflamed Gums Can Heal
If your inflammation is at the gingivitis stage, meaning no bone loss has occurred, recovery is straightforward. The Mayo Clinic notes that healthy gum tissue can return within days to weeks once you improve your brushing and flossing routine and follow up with a professional cleaning. A dental hygienist removes the hardened plaque (tartar) that you can’t brush away at home, which gives your gums a clean surface to heal against.
The key habits that matter most are brushing twice a day with a soft-bristled brush, flossing daily (gently), and keeping up with regular cleanings. If your gums bleed when you first start flossing again after a break, that’s normal and typically stops within a week or two as the tissue heals.
When Inflammation Has Gone Further
Periodontitis is staged by how deep the pockets between your gums and teeth have become. Healthy pockets measure 1 to 3 millimeters. In Stage I (mild) periodontitis, pockets reach up to 4 millimeters. Stage II (moderate) extends to 5 millimeters. Stages III and IV involve pockets of 6 millimeters or deeper, along with significant bone loss.
Unlike gingivitis, periodontitis isn’t fully reversible. The goal shifts to stopping progression and managing the condition. Treatment typically starts with a deep cleaning called scaling and root planing, where tartar is removed from below the gumline and root surfaces are smoothed to help gums reattach. More advanced cases may require surgical intervention. The earlier periodontitis is caught, the more tissue and bone you preserve, which is why persistent gum inflammation that doesn’t respond to improved home care within a couple of weeks is worth getting evaluated.