Gum pain is most often caused by a buildup of bacterial plaque along the gumline, which triggers inflammation, swelling, and soreness. But plaque isn’t the only culprit. Hormonal shifts, nutritional gaps, infections, and even brushing too hard can all make your gums hurt. Understanding the specific cause matters because some sources of gum pain resolve on their own in days, while others signal damage that can lead to tooth loss if ignored.
Plaque Buildup and Gum Disease
The most common reason gums become painful is gum disease, and it starts with plaque. Plaque is a thin, barely visible film of bacteria that coats your teeth throughout the day. These bacteria feed on sugars in your food, and their waste products irritate gum tissue, causing it to swell, redden, and bleed. This early stage is called gingivitis, and its hallmark signs are gums that bleed when you brush or sometimes for no obvious reason at all.
Gingivitis is reversible with consistent cleaning, but if it lingers, it progresses into something more destructive: periodontitis. As inflammation deepens, pockets form between your teeth and gums. Healthy gum pockets measure 1 to 3 millimeters. With gingivitis, they reach about 4 millimeters. In periodontitis, they hit 5 millimeters or more, sometimes exceeding a centimeter. Bacteria colonize these deepening pockets and spread down toward the tooth root, attacking the soft tissue and bone that hold your teeth in place. At advanced stages, periodontitis causes receding gums, persistent soreness, pain while chewing, teeth that shift position, and teeth that wobble.
Gum disease is extraordinarily common. About 42% of U.S. adults over 30 have some form of periodontitis, and that number climbs to nearly 60% for adults over 65. Plaque that hardens into tartar (calculus) along the gumline can only be removed by a dental professional, which is why regular cleanings matter even if you brush diligently.
Dental Abscesses
A dental abscess is a pocket of pus caused by a bacterial infection, and it produces some of the most intense gum pain you can experience. The pain is typically severe, constant, and throbbing. It can radiate from the gum into your jawbone, neck, or ear. You may also notice swelling in your face or cheek, tender lymph nodes under your jaw, sensitivity to hot and cold, pain when biting down, fever, and persistent bad breath.
If an abscess ruptures on its own, you’ll taste a sudden rush of salty, foul-smelling fluid, and the pain may temporarily ease. That doesn’t mean the infection is gone. Left untreated, an abscess can damage surrounding teeth and bone, and the infection can spread to your jaw, throat, or neck. Fever combined with facial swelling or any difficulty breathing or swallowing is a reason to go to an emergency room, not wait for a dental appointment.
Brushing Too Hard
Aggressive brushing is a surprisingly common source of gum pain. Pressing too hard or using a stiff-bristled toothbrush can wear away gum tissue over time, leading to gum recession. As gums pull back, they expose the sensitive root surfaces of your teeth, which causes both gum soreness and sharp sensitivity to temperature. The damage is gradual, so many people don’t connect their brushing habits to the pain until recession is already visible. Switching to a soft-bristled brush and using gentle, short strokes instead of scrubbing can stop further damage.
Canker Sores on the Gums
Canker sores (aphthous ulcers) are small, shallow lesions that commonly appear inside the lips, on the cheeks, or on the tongue, but they can also develop on gum tissue. They produce a localized, stinging pain that flares when you eat or brush. Most canker sores heal within 7 to 14 days without treatment, though they tend to recur. The exact cause isn’t fully understood, but stress, minor mouth injuries (like biting your cheek), acidic foods, and immune system factors all play a role. If a sore on your gums doesn’t heal within two weeks, it’s worth having it evaluated.
Hormonal Changes
Fluctuations in estrogen and progesterone can make gum tissue more reactive to even small amounts of plaque. Gum tissue contains receptors for sex hormones, which means the body’s hormonal shifts directly influence how inflamed your gums become. Rising progesterone increases blood flow to the gums and makes tiny blood vessels more permeable, which amplifies swelling, bleeding, and soreness. It also interferes with the normal repair process in gum tissue.
This is why gum pain often spikes during specific life stages. During puberty, elevated hormone levels increase gum sensitivity to plaque, a condition sometimes called puberty gingivitis. Many women notice gums that bleed or ache in the days before their period. Pregnancy is another common trigger. The key detail is that hormones don’t cause gum disease on their own. They amplify the body’s inflammatory response to plaque that’s already there. Maintaining thorough oral hygiene during these periods limits how much influence hormonal shifts have on gum health.
Nutritional Deficiencies
Your gums need specific nutrients to stay healthy, and deficiencies can show up in your mouth before you notice symptoms elsewhere. Vitamin C is essential for maintaining the connective tissue in your gums. A severe deficiency (scurvy) causes gums to swell, bleed easily, and become painful. While full-blown scurvy is rare in developed countries, milder vitamin C shortfalls can still contribute to gum problems.
Vitamin B12 deficiency produces a different set of oral symptoms: burning sensations in the tongue, lips, and inner cheeks, recurring mouth ulcers, and red, inflamed patches on the oral mucosa. Oral changes appear in 50 to 60% of patients with the type of anemia caused by B12 deficiency. These symptoms can mimic other conditions, so persistent burning or unexplained redness in the mouth is worth mentioning to your dentist or doctor, especially if you follow a diet low in animal products.
Smoking and Tobacco Use
Smoking is one of the strongest risk factors for gum disease, and it works through a mechanism that makes it particularly dangerous. Tobacco smoke suppresses the immune system’s inflammatory response in gum tissue. Smokers have lower levels of several key immune signaling molecules that normally alert the body to infection. The result is a paradox: smokers harbor more of the bacteria that cause gum disease, yet their gums often look less inflamed than they should. Bleeding and redness are reduced, which masks the severity of what’s happening underneath.
This means smokers frequently don’t notice gum problems until significant damage has already occurred. By the time pain, recession, or loose teeth become obvious, the disease is often advanced. Tobacco also slows healing after dental procedures, compounding the problem.
Other Common Triggers
Several additional factors can cause or contribute to gum pain:
- Ill-fitting dental appliances. Dentures, retainers, or mouthguards that don’t fit properly can rub against gum tissue, creating sore spots or ulcers.
- Impacted or erupting teeth. Wisdom teeth that are partially erupted or stuck beneath the gumline often cause localized pain, swelling, and sometimes infection in the surrounding tissue.
- Teeth grinding (bruxism). Chronic clenching or grinding puts excessive pressure on teeth and the supporting gum and bone structures, leading to soreness that’s often worst in the morning.
- Food trapped between teeth. A popcorn hull or seed lodged under the gumline can cause sharp, localized pain and swelling that resolves once the debris is removed with floss.
When Gum Pain Needs Urgent Attention
Most gum pain from minor irritation, canker sores, or early gingivitis improves within a week or two with good oral hygiene. But certain signs indicate something more serious. Severe throbbing pain that doesn’t respond to over-the-counter pain relief, visible pus or a pimple-like bump on the gum, teeth that feel loose, bleeding that won’t stop, or facial swelling paired with fever all point to conditions that can worsen quickly without professional care. An abscess in particular can spread beyond the mouth, and facial swelling with difficulty breathing or swallowing is a medical emergency.