Swollen gums are most often caused by a buildup of plaque along the gumline, which triggers inflammation known as gingivitis. Over 42% of American adults aged 30 and older have some form of gum disease, making it one of the most common reasons your gums might be puffy, tender, or red. But plaque isn’t the only possibility. Infections, hormonal changes, certain medications, and even nutritional gaps can all cause gum tissue to swell.
Plaque Buildup and Early Gum Disease
The most common culprit is gingivitis, the earliest stage of gum disease. Plaque, a sticky film of bacteria, constantly forms on your teeth. When it isn’t removed through regular brushing and flossing, it irritates the gum tissue and triggers an inflammatory response. The telltale signs are red, puffy gums that bleed when you brush or floss.
The tricky part is that gingivitis often causes no pain at all. Many people have it without realizing it, which means the swelling you’re noticing now may have been developing for a while. The good news is that gingivitis is fully reversible with better oral hygiene and a professional cleaning. Left untreated, though, it can progress to periodontitis, a more advanced form of gum disease that damages the bone supporting your teeth and can eventually lead to tooth loss.
Infection or Abscess
If the swelling is concentrated around a single tooth and comes with throbbing pain, you may be dealing with a dental abscess. This is a pocket of pus caused by a bacterial infection. One type forms at the tip of a tooth’s root, typically from an untreated cavity. The other forms in the gum tissue alongside a tooth root, often related to advanced gum disease or trapped food debris.
An abscess won’t resolve on its own. It needs professional treatment to drain the infection and address the underlying cause. If swelling spreads to your face, neck, or under your jaw, or if you develop a fever, difficulty swallowing, or trouble breathing, that signals the infection is spreading beyond your mouth and requires emergency care.
Hormonal Changes
Hormonal shifts, particularly during pregnancy, can make your gums noticeably more swollen even if your oral hygiene hasn’t changed. Rising levels of estrogen and progesterone increase blood flow to gum tissue, making it more prone to inflammation, soreness, and bleeding. These same hormones also change how your gums react to plaque, essentially lowering the threshold for irritation.
This condition, sometimes called pregnancy gingivitis, is common enough that many pregnant people experience it to some degree. Menstrual cycles and puberty can trigger similar, milder versions of the same response. The swelling typically improves once hormone levels stabilize, but keeping up with brushing and flossing during these periods is especially important to prevent it from progressing.
Medications That Cause Gum Overgrowth
Certain medications can cause gum tissue to physically enlarge, a side effect that often surprises people. Three categories of drugs are the main offenders:
- Anti-seizure medications: Phenytoin is the most well-known trigger. Roughly half of the 2 million people taking it develop some degree of gum overgrowth. Other anti-seizure drugs, including valproic acid and carbamazepine, carry similar risk.
- Blood pressure medications (calcium channel blockers): Nifedipine causes gum enlargement in about 38% of users. Diltiazem and verapamil also carry risk, though at lower rates.
- Immunosuppressants: Cyclosporine, used after organ transplants and for autoimmune conditions, causes gum overgrowth in anywhere from 13% to 85% of patients depending on the study.
If you started a new medication in the weeks or months before your gums began swelling, it’s worth discussing the timing with your prescriber. Don’t stop any medication on your own, but alternatives may be available.
Vitamin C Deficiency
Your gums depend on vitamin C to maintain their structural integrity. This vitamin is essential for producing collagen, the protein that holds gum tissue and blood vessels together. When levels drop too low, blood vessels in the gums weaken, leading to increased redness, swelling, and bleeding.
True vitamin C deficiency (scurvy) is rare in developed countries, but milder shortfalls are more common than you might expect, particularly in people with very restrictive diets, smokers, or those with conditions that impair nutrient absorption. If your gum swelling is accompanied by fatigue, easy bruising, or slow wound healing, low vitamin C could be a contributing factor.
What You Can Do at Home
While home care can’t replace professional treatment for infections or advanced gum disease, it can reduce mild swelling and support healing. A warm saltwater rinse is one of the simplest tools: dissolve 1 teaspoon of salt in 8 ounces of warm water and swish gently for 30 seconds. If that feels too strong, cut the salt to half a teaspoon. This helps draw out excess fluid from inflamed tissue and creates an environment that’s less friendly to bacteria.
Beyond rinses, the basics matter most. Brush twice daily with a soft-bristled toothbrush, paying careful attention to the gumline where plaque accumulates. Floss daily, even if your gums bleed at first. That bleeding is a sign of inflammation, not a reason to stop. It typically improves within a week or two of consistent flossing as the gum tissue heals.
What Happens at a Professional Cleaning
If plaque has hardened into tartar (calculus), no amount of brushing will remove it. You’ll need a professional cleaning. For mild gingivitis, a standard cleaning may be enough. For more advanced buildup, your dentist may recommend a deep cleaning called scaling and root planing.
During this procedure, your gums are numbed with a local anesthetic. Your dentist or hygienist then removes plaque and tartar from both above and below the gumline, then smooths the tooth roots so gum tissue can reattach more easily. The whole process takes one to two hours, sometimes split across two visits. Most people return to their normal routine the same day.
Afterward, your gums may feel sore for a couple of days, and your teeth might be temporarily sensitive to hot and cold as the newly cleaned surfaces adjust. Some people notice their teeth feel slightly loose right after, but this resolves as the gums tighten back up. As swelling goes down, your gums may appear to recede slightly, revealing a bit more of your tooth roots. This is actually a sign that inflammation is resolving, not a sign of damage.
Signs That Need Urgent Attention
Most gum swelling is not an emergency, but certain combinations of symptoms mean an infection could be spreading and needs immediate care. Get seen the same day if your swollen gums come with a high fever, pus draining from the gum, constant throbbing pain, or numbness in your lip or face. Swelling that grows rapidly, spreads toward your neck or eye area, or makes it difficult to open your mouth, chew, swallow, or breathe is a medical emergency.