Gum disease starts when bacterial plaque, the sticky film that naturally builds up on your teeth, triggers an inflammatory response in your gum tissue. About 42% of American adults age 30 and older have some form of periodontitis, and that number climbs to nearly 60% in adults 65 and older. While plaque buildup is the root cause, a range of factors from smoking to diabetes to certain medications can accelerate the process or make your body less able to fight it off.
Plaque Buildup Is the Starting Point
Your mouth is home to hundreds of species of bacteria. Most are harmless, but when plaque sits on your teeth undisturbed, the bacterial community shifts. Harmful species begin to dominate, especially in the warm, sheltered space between your teeth and gums. These bacteria release toxins that irritate gum tissue and trigger your immune system to respond with inflammation.
If plaque isn’t removed through brushing and flossing, it hardens into tarite (also called calculus) within 24 to 72 hours. Tartar can’t be removed at home. It clings to the tooth surface at and below the gumline, giving bacteria a rough, protected surface to keep multiplying on. This is why regular dental cleanings matter: they remove the hardened deposits that daily brushing misses.
Gingivitis: The Early, Reversible Stage
The first stage of gum disease is gingivitis, and it’s more common than most people realize. Clinically, gingivitis is defined by gums that bleed when probed or flossed, but with no bone loss beneath the surface. Pocket depths between the gum and tooth stay at 3 millimeters or less, and X-rays show no deterioration of the jawbone.
You might notice your gums look red or puffy, or that you see pink on your toothbrush or when you spit after brushing. Some people have no obvious symptoms at all. The good news is that gingivitis is fully reversible with consistent oral hygiene and professional cleaning. The gum tissue heals because no permanent structural damage has occurred yet.
Periodontitis: When Damage Becomes Permanent
When gingivitis goes untreated, it can progress to periodontitis. This is where the inflammation starts destroying the bone and connective tissue that hold your teeth in place. The pockets between your gums and teeth deepen beyond 4 millimeters, creating spaces where bacteria thrive even further out of reach of your toothbrush.
What actually destroys the bone isn’t the bacteria directly. It’s your own immune system. When certain immune cells detect the ongoing bacterial infection, they release signaling molecules that ramp up inflammation. One key signal, called IL-17, stimulates bone-building cells to instead produce a protein that activates bone-destroying cells. Essentially, your body’s defense response goes into overdrive and starts breaking down the very structures it’s trying to protect. Once bone is lost, it doesn’t grow back on its own. Teeth loosen, shift, and can eventually fall out.
Smoking and Tobacco Use
Smoking is one of the strongest risk factors for gum disease. Nicotine constricts blood vessels in the gum tissue, reducing the flow of oxygen and nutrients that gums need to stay healthy and heal. At the same time, smoking suppresses your immune system’s ability to fight bacterial infections in the mouth. This creates a double problem: bacteria flourish while your body’s defenses are weakened.
Smokers also tend to have a deceptive presentation of gum disease. Because nicotine restricts blood flow, their gums may not bleed as readily, masking one of the earliest warning signs. By the time symptoms become obvious, the disease is often more advanced. Quitting tobacco at any stage improves your gum health and your body’s ability to respond to treatment.
How Diabetes Accelerates Gum Disease
Diabetes and gum disease have a two-way relationship. Poorly controlled blood sugar creates a persistent inflammatory state throughout the body, and the mouth is no exception. High glucose levels also change the environment inside your mouth in several specific ways.
First, diabetes impairs salivary gland function. Saliva normally washes bacteria off teeth and neutralizes acids. When saliva production drops or its chemistry changes, the mouth becomes more acidic, favoring the growth of harmful, acid-resistant bacteria while suppressing beneficial species. Research has found that people with diabetes carry higher levels of specific periodontal pathogens, and that these bacterial levels correlate directly with blood sugar control.
Second, high blood sugar reduces your body’s ability to produce anti-inflammatory signals. One of the body’s key inflammation-dampening molecules becomes less effective under hyperglycemic conditions, so the inflammatory cycle in gum tissue persists longer and causes more damage. Diabetes also impairs tissue regeneration, meaning gums and bone heal more slowly after injury or treatment. People with well-controlled blood sugar have significantly better periodontal outcomes than those with poorly managed diabetes.
Medications That Affect Your Gums
Certain prescription drugs can cause gum overgrowth, a condition where gum tissue swells and grows over the teeth. This overgrowth creates deep pockets that trap bacteria and make oral hygiene much harder. Three drug classes are most commonly involved: anti-seizure medications, blood pressure medications (specifically calcium channel blockers), and immunosuppressants used after organ transplants.
Roughly 40 to 50% of people taking these medications develop some degree of gum overgrowth. Among calcium channel blockers, nifedipine carries the highest incidence at about 38%, while others in the same class range from 3 to 20%. The anti-seizure medication phenytoin affects about half of its roughly 2 million users. If you take any of these medications and notice your gums looking thicker or growing over your teeth, your dentist can work with your prescribing doctor to adjust your treatment. Meticulous plaque control helps reduce the severity.
Nutritional Deficiencies
Vitamin C plays a direct role in maintaining gum health because your body needs it to build and repair collagen, the protein that gives structure to your gums, skin, and connective tissue. When vitamin C intake drops too low, gums become swollen, spongy, and prone to bleeding. In severe deficiency (scurvy), gums can turn purple and teeth may loosen or fall out. While full-blown scurvy is rare today, milder vitamin C insufficiency is not, and it can contribute to gum tissue that’s more vulnerable to bacterial damage and slower to heal.
Severe gum damage from prolonged vitamin C deficiency can cause permanent changes even after levels are restored, with dental and gum recovery taking weeks to months.
Other Factors That Raise Your Risk
Age is a major factor. Gum disease prevalence rises steadily with each decade, reaching nearly 60% in adults over 65. This reflects a lifetime of cumulative exposure to plaque, but also age-related changes in immune function and tissue repair.
Hormonal shifts during pregnancy, puberty, and menopause increase blood flow to the gums and change how gum tissue responds to bacteria, making inflammation more likely even with the same level of plaque. Genetics also play a role. Some people mount a more aggressive inflammatory response to oral bacteria than others, making them more susceptible to tissue and bone destruction even with good hygiene habits.
Chronic stress and conditions like rheumatoid arthritis contribute as well. People with rheumatoid arthritis show greater loss of gum attachment and higher levels of inflammatory markers in their periodontal tissue, linked to both increased bacterial load and a ramped-up immune response. Anything that keeps your immune system in a state of chronic activation can tip the balance toward tissue breakdown in the gums.
Why Early Gum Disease Is Easy to Miss
One of the reasons gum disease is so widespread is that the early stage rarely hurts. Gingivitis can be present for months or years with nothing more than occasional bleeding during brushing, something many people dismiss as normal. There’s no sharp pain, no visible decay, no obvious problem. By the time you notice persistent bad breath, receding gums, or teeth that feel loose, the disease has likely already caused irreversible bone loss. Consistent daily flossing and brushing along the gumline, combined with professional cleanings, remain the most effective way to catch and reverse gum disease before it reaches that point.