Gum disease starts with bacterial plaque, the sticky film that builds up on your teeth every day. Nearly 46% of adults between 45 and 64 have some form of periodontitis, and that number climbs to roughly 60% for adults 65 and older. While plaque is the root cause, a range of factors from smoking to hormonal shifts to certain medications can accelerate the damage or make your gums more vulnerable to it.
Plaque: The Starting Point
Every time you eat, bacteria in your mouth feed on leftover sugars and starches. These bacteria don’t just float around loosely. They organize into a structured community called a biofilm, layering themselves onto your teeth and producing a slimy protective coating made of proteins, cell debris, and sticky sugars. This coating shields the bacteria from both your immune system and from things like mouthwash, making the colony harder to disrupt the longer it sits.
In the earliest hours, this film is soft and easy to brush away. But if it stays on your teeth, it begins to harden. Plaque can start mineralizing into tartar (also called calculus) within one to 14 days, reaching 60% to 90% of its full hardness by about day 12. Once that happens, no amount of brushing or flossing at home will remove it. You need a professional cleaning.
As bacteria multiply, they produce acids and waste products that irritate the gum tissue right at the gumline. Your immune system responds with inflammation: redness, swelling, and bleeding when you brush. This early stage is called gingivitis, and it’s reversible. With consistent brushing, flossing, and a professional cleaning, healthy gum tissue can return within days to weeks. Left alone, though, the infection creeps deeper.
How Gingivitis Becomes Periodontitis
When plaque and tartar remain below the gumline for weeks or months, the inflammation starts doing real structural damage. Your gums begin pulling away from the teeth, forming pockets that trap even more bacteria. Certain aggressive species thrive in these low-oxygen pockets and produce enzymes that break down the connective tissue holding your teeth in place. They can also trigger your body’s bone-dissolving cells, leading to irreversible bone loss around the tooth roots.
This progression from surface inflammation to deep tissue and bone destruction is the difference between gingivitis and periodontitis. Gingivitis is like a warning light. Periodontitis is the engine damage that follows if you ignore it. Among adults 30 to 44, about 4% already have severe periodontitis. By ages 45 to 64, that rate jumps to over 10%.
Smoking and Tobacco Use
Smoking is one of the strongest risk factors for gum disease. Tobacco changes the way your immune system responds to bacteria in plaque. Specifically, it suppresses the inflammatory signals your body needs to fight off infection at the gum line while simultaneously reducing blood flow to the gums. Less blood flow means less oxygen and fewer immune cells reaching the tissue, so bacteria can establish deeper colonies with less resistance. Smokers also tend to accumulate more tartar, develop deeper gum pockets, and lose bone faster than nonsmokers. Healing after dental treatment is slower, too, because the same restricted blood supply that lets the disease progress also impairs tissue repair.
Diabetes and Blood Sugar
Poorly controlled diabetes and gum disease have a two-way relationship. High blood sugar impairs your white blood cells, weakening your body’s ability to fight the bacterial infection in your gums. At the same time, the chronic inflammation from gum disease can make blood sugar harder to control, creating a cycle that worsens both conditions. People with inadequately managed diabetes experience more severe breakdown of gum and bone tissue than people with the same amount of plaque but normal blood sugar levels.
Hormonal Changes
Pregnancy is a well-documented trigger for gum inflammation, even in women who had healthy gums before. Rising levels of estrogen and progesterone during pregnancy affect gum tissue in several ways at once. These hormones increase blood flow to the gums, making the tissue more reactive to even small amounts of plaque. They also act as a growth factor for certain harmful bacteria, directly fueling their reproduction. One key species linked to gum disease actually uses progesterone as a nutrient substitute, which helps explain why bacterial counts spike during pregnancy.
On top of that, pregnancy hormones impair the function of neutrophils, the white blood cells that serve as your gums’ first line of defense. With weaker immune surveillance and a larger bacterial population, inflammation increases. Pregnant women commonly notice deeper gum pockets and more bleeding during brushing. The good news is that these changes typically resolve after delivery once hormone levels return to normal.
Puberty, menstruation, and menopause can trigger similar (though usually milder) shifts in gum sensitivity for the same hormonal reasons.
Medications That Affect Your Gums
Several common drug classes can cause gum overgrowth, a condition where the tissue swells and grows over parts of your teeth. The excess tissue creates folds and pockets that are difficult to keep clean, trapping plaque and raising your risk of infection.
The three main categories are:
- Seizure medications: About 50% of adults taking phenytoin, one of the most commonly prescribed anticonvulsants, develop noticeable gum enlargement.
- Immune-suppressing drugs: Roughly 30% of people on cyclosporine (often prescribed after organ transplants) experience gum overgrowth. Among kidney transplant recipients specifically, the rate is even higher, around 53%.
- Blood pressure medications: Calcium channel blockers like nifedipine and amlodipine cause gum overgrowth in about 20% of users.
Hundreds of other medications contribute to gum disease indirectly by causing dry mouth. Saliva is your mouth’s natural rinse cycle, constantly washing bacteria off tooth surfaces and neutralizing acids. When saliva production drops, plaque accumulates faster. Antihistamines, antidepressants, and decongestants are common culprits.
Age and Genetics
Gum disease becomes dramatically more common as you get older. About 30% of adults in their 30s have some form of periodontitis, compared to nearly 60% of those 65 and older. Part of this is cumulative exposure: decades of plaque buildup and minor tissue damage add up. But aging also brings changes in immune function and bone density that make the tissue more vulnerable.
Genetics play a role too. Some people mount an exaggerated inflammatory response to the same bacterial load that barely bothers someone else. If your parents lost teeth to gum disease, you may be genetically predisposed to more aggressive tissue breakdown, which makes consistent preventive care even more important.
Other Contributing Factors
Nutritional deficiencies, particularly low vitamin C, weaken the connective tissue in your gums and slow healing. Chronic stress raises levels of the hormone cortisol, which dampens immune function and has been linked to higher rates of periodontal disease. Teeth grinding (bruxism) doesn’t cause gum disease directly, but the excessive force on teeth can accelerate bone loss in areas already weakened by infection.
Crooked or crowded teeth create hard-to-reach crevices where plaque accumulates. Poorly fitting dental restorations, like old crowns or bridges with rough edges, can trap bacteria against the gumline. Even mouth breathing, which dries out the gums, removes the protective effect of saliva and leaves tissue more prone to inflammation.