Swollen gums are most often caused by plaque buildup along the gumline, which triggers an inflammatory response called gingivitis. About 42% of American adults over 30 have some form of periodontal disease, making this one of the most common health issues people experience. But plaque isn’t the only culprit. Hormonal shifts, nutritional deficiencies, infections, certain medications, and even serious systemic illnesses can all cause your gums to puff up.
Plaque Buildup and Gingivitis
The most common reason gums swell is simple: bacteria-laden plaque accumulates where your teeth meet your gums, and your immune system responds with inflammation. When plaque isn’t removed through regular brushing and flossing, it hardens into tarite (calculus), which you can’t remove at home. The longer it sits there, the more irritated your gum tissue becomes.
Early gingivitis causes redness, puffiness, and bleeding when you brush or floss. At this stage, the damage is reversible. Left untreated, gingivitis can progress to periodontitis, where the inflammation starts destroying the bone and connective tissue that hold your teeth in place. Of those 42% of adults with periodontal disease, about 8% have the severe form, which involves significant bone loss and potential tooth loss.
Hormonal Changes
Pregnancy is one of the best-known hormonal triggers for gum swelling. Rising levels of estrogen and progesterone increase blood flow to the gums, making them more prone to inflammation, soreness, and bleeding. These hormones also change how sensitive your gum tissue is to plaque, so even a normal amount of bacterial buildup can provoke a stronger inflammatory reaction than it would otherwise. This is common enough to have its own name: pregnancy gingivitis.
Puberty and menstruation can produce similar effects on a smaller scale. During these hormonal shifts, gums may feel tender or look redder than usual, even if your oral hygiene hasn’t changed. The swelling typically resolves once hormone levels stabilize, but it still requires consistent brushing and flossing to keep from worsening.
Vitamin C Deficiency
Your gums depend on vitamin C to maintain the collagen that gives them their structure. When you’re not getting enough, the tiny blood vessels in your gum tissue weaken, leading to increased redness, swelling, and bleeding. Severe deficiency (scurvy) is rare in developed countries, but marginal deficiency is more common than most people realize, particularly in smokers, older adults, and people with very limited diets.
Vitamin C also appears to play a role in controlling histamine levels in gum tissue. When levels drop too low, excess histamine production may amplify the inflammatory response to everyday irritants like plaque. This means even minor gum irritation can spiral into visible swelling if your vitamin C intake is consistently low.
Dental Abscesses
An abscess is a pocket of pus caused by bacterial infection, and it can produce dramatic, localized gum swelling that comes on quickly and hurts. There are two main types, distinguished by where the infection starts.
A periapical abscess begins inside the tooth. Bacteria enter through decay, a crack, or a chip in the enamel, infect the inner tissue near the nerve, and the infection travels down to the root tip. You’ll typically feel a deep, throbbing ache centered on one tooth, and the gum near the root may swell into a visible bump.
A periodontal abscess starts in the gum tissue itself, usually alongside the root of a tooth. These are more commonly associated with existing gum disease or an injury to the gum. The swelling tends to appear right at the gumline rather than deeper near the jaw. Both types require professional treatment, as the infection won’t resolve on its own and can spread to surrounding tissue or bone.
Medications That Cause Gum Overgrowth
Several classes of medication can cause gums to gradually thicken and swell, sometimes to the point where they begin growing over the teeth. The three main categories are immunosuppressants (used after organ transplants), certain anti-seizure medications, and calcium channel blockers (used for high blood pressure and heart conditions). If you’ve started a new medication and notice your gums looking puffy or growing larger over weeks to months, your prescribing doctor and dentist should both know about it. The overgrowth is often manageable with meticulous oral hygiene and professional cleanings, though some cases require adjusting the medication.
Systemic Illnesses
In rare cases, swollen gums can be an early sign of something more serious happening in the body. Gum overgrowth appears as the first noticeable symptom in about 5% of acute leukemia cases. In certain subtypes, the rate is much higher: roughly two-thirds of people with acute monocytic leukemia develop significant gum swelling. This happens because abnormal white blood cells infiltrate the gum tissue in large numbers, causing it to enlarge.
Other systemic conditions linked to gum overgrowth include Crohn’s disease, sarcoidosis, and tuberculosis, as well as rare hereditary conditions. These causes are uncommon, but they’re worth knowing about, especially if your gum swelling doesn’t respond to improved oral hygiene, appears suddenly without an obvious dental cause, or comes with other unexplained symptoms like fatigue, easy bruising, or unexplained weight loss.
What Helps Swollen Gums Heal
For most people, the fix starts with better plaque control. Brushing twice daily with a soft-bristled brush, flossing once a day, and using an antiseptic mouthwash can reverse mild gingivitis within a couple of weeks. A warm saltwater rinse (half a teaspoon of salt in eight ounces of warm water) can also help reduce inflammation and draw out minor irritation in the short term.
If plaque has already hardened into tartar below the gumline, you’ll need a professional deep cleaning, sometimes called scaling and root planing. Your dentist or hygienist removes the buildup from beneath the gums and smooths the root surfaces so the tissue can reattach. Expect some discomfort for a day or two afterward, with gum sensitivity lasting up to a week. Full healing of the gum tissue generally takes four to six weeks.
For swelling caused by hormones, the inflammation usually improves once levels normalize, but staying on top of brushing and flossing during those periods makes a real difference. Nutritional causes respond to correcting the deficiency. Abscesses need drainage and often antibiotics. Medication-related gum overgrowth may require a conversation about alternative drugs. In every case, identifying the underlying cause is what determines whether the swelling goes away and stays away.