A swollen, painful gum usually means your body is reacting to an irritant, whether that’s trapped bacteria, an injury, or an infection brewing beneath the surface. The cause can range from something minor like a food particle wedged under the gumline to something more serious like an abscess. Most cases improve within a few days with proper care, but certain warning signs call for prompt attention.
The Most Common Causes
Gum inflammation from plaque buildup, called gingivitis, is by far the most frequent reason gums swell and hurt. About 4 in 10 U.S. adults over age 30 have some level of gum disease. In its earliest stage, plaque (the sticky bacterial film that forms on teeth) irritates gum tissue, making it red, puffy, and tender. At this point, the damage is reversible with better brushing and flossing habits.
If the swelling is focused around a single tooth and the pain is intense or throbbing, an abscess is more likely. There are two main types. A periapical abscess starts inside the tooth, usually from deep decay, and causes throbbing pain that can radiate to your ear, neck, or jaw, along with sensitivity to hot and cold. A periodontal abscess forms in the gum tissue itself, often appearing as a visible bump or boil near the tooth. Both types involve trapped pus and won’t resolve on their own.
Other common triggers include food caught beneath the gumline, a canker sore on the gum tissue, irritation from a rough dental restoration or orthodontic wire, or a partially erupted wisdom tooth where bacteria collect under a flap of gum.
Less Obvious Reasons Your Gums Hurt
Hormonal shifts can make gums dramatically more sensitive to plaque. During pregnancy, rising estrogen and progesterone levels increase blood flow to gum tissue, amplify the inflammatory response to even small amounts of plaque, and can change the size and shape of the gums. This is common enough to have its own name: pregnancy gingivitis. Puberty, menstruation, and menopause can trigger similar flare-ups.
Low vitamin C intake is another overlooked cause. Research pooling data from over 9,000 people found that low blood levels of vitamin C were linked to increased gum bleeding, even with gentle probing. Severe deficiency (scurvy) causes pronounced gum swelling and bleeding. The recommended daily intake is 90 mg for adult men and 75 mg for women. Foods like bell peppers, kiwis, oranges, and kale are rich sources, and a 100 to 200 mg daily supplement can help close the gap.
Certain medications, particularly some blood pressure drugs, anti-seizure medications, and immunosuppressants, can cause gum overgrowth that makes tissue puffy and sore. If your swelling started after beginning a new medication, that connection is worth exploring with your prescriber.
How to Reduce Pain and Swelling at Home
A warm saltwater rinse is one of the simplest and most effective first steps. Mix 1 teaspoon of salt into 8 ounces of warm water. Swish gently for 30 seconds and spit. If your mouth is very tender, cut the salt to half a teaspoon for the first day or two. Repeat two to three times a day. The salt draws fluid out of swollen tissue and creates an environment that’s harder for bacteria to thrive in.
For pain relief, the combination of ibuprofen and acetaminophen is more effective than either one alone. The American Dental Association notes that 400 mg of ibuprofen combined with 500 to 1,000 mg of acetaminophen outperformed even opioid-containing regimens in studies involving over 58,000 dental patients. For milder pain, 200 to 400 mg of ibuprofen alone every four to six hours is usually enough. These two medications work through completely different pathways, which is why combining them provides stronger relief without increasing the dose of either one.
Avoid very hot or very cold foods and drinks if the area is sensitive. Brush gently around the sore spot with a soft-bristled toothbrush rather than skipping it entirely. Skipping that area lets bacteria accumulate and makes the problem worse. If you suspect food is trapped, try gently sliding floss along the tooth or using an interdental brush.
When Swelling Signals Something Serious
Most gum swelling improves within a few days. But certain symptoms suggest the infection is spreading beyond the gum and requires urgent care:
- Swelling extending to the face, cheek, or neck
- Fever
- Difficulty swallowing or breathing
- Trouble opening your mouth (a condition called trismus)
- Nausea or vomiting alongside dental pain
- Vision changes, severe headache, or confusion
These are signs that a dental infection may be affecting nearby tissue or entering the bloodstream. Facial swelling that’s getting noticeably worse over hours, rather than days, is particularly concerning.
What Happens if You Don’t Treat It
Gingivitis that goes untreated progresses to periodontitis, where the infection moves deeper and starts destroying the bone that holds your teeth in place. Dentists measure this by checking the depth of the pocket between your gum and tooth with a small probe. Healthy gums measure 1 to 3 millimeters. Pockets of 4 to 5 millimeters indicate early periodontitis. At 5 to 7 millimeters, the disease is moderate, and readings above 7 millimeters mean advanced bone loss that can lead to loose or lost teeth.
The progression from gingivitis to periodontitis isn’t inevitable. Gingivitis is fully reversible because the bone hasn’t been damaged yet. Once bone loss begins, though, you can only stop further damage, not regenerate what’s already gone. That distinction is the strongest argument for addressing swollen gums early rather than waiting to see if they improve on their own.
What to Expect at the Dentist
If your swelling doesn’t improve within a few days, keeps coming back, or is accompanied by a visible bump on the gum, a dental visit will clarify what’s going on. The dentist will probe around the affected area, take X-rays to check for bone loss or infection at the tooth root, and look for pockets of pus.
For gingivitis, a professional cleaning to remove hardened plaque (tarite) below the gumline is often all that’s needed, combined with improved home care. For an abscess, the priority is draining the infection. This usually provides near-immediate pain relief. Antibiotics may follow if the infection is widespread. For periodontitis, a deeper cleaning called scaling and root planing smooths the tooth roots so gums can reattach, and follow-up visits track whether pockets are shrinking.
Recovery from a professional cleaning is quick. Gums may be tender for a day or two. After abscess drainage, pain drops sharply within hours, though some soreness lingers for a few days as the tissue heals.