Gum disease starts with inflamed, bleeding gums and, if left untreated, progressively destroys the bone and tissue holding your teeth in place. Nearly 46% of adults aged 45 to 64 have some form of periodontitis, and that number climbs to about 60% for those 65 and older. What begins as a nuisance you might brush off can escalate into tooth loss, chronic pain, and health complications that reach well beyond your mouth.
How Gum Disease Starts
It begins with bacteria. A sticky film of bacteria called plaque builds up on your teeth daily. When plaque isn’t removed through brushing and flossing, it hardens into tarite (calculus) that you can’t clean off yourself. The bacteria in this buildup irritate your gums, triggering inflammation. At this stage, the condition is called gingivitis, and the signs are straightforward: red or purplish gums, swelling, tenderness, and bleeding when you brush or floss.
Gingivitis is the one stage of gum disease that’s fully reversible. With improved oral hygiene and a professional cleaning, the inflammation can resolve completely without lasting damage. The problem is that gingivitis often doesn’t hurt, so many people ignore it.
What Happens When It Progresses
When gingivitis goes untreated, bacteria work their way below the gumline and the condition crosses into periodontitis, a more serious infection that damages the bone supporting your teeth. This transition is a one-way door. The CDC is clear on this point: periodontitis is irreversible. It can be slowed and managed, but the bone you lose doesn’t grow back on its own.
Periodontitis is classified in stages based on severity:
- Stage I (initial): Mild gum bleeding, slight pocketing around teeth (about 4 mm deep), and minimal bone loss visible on X-rays.
- Stage II (moderate): Pockets deepen to 5 or 6 mm, more bone loss appears, and you may notice early tooth looseness or sensitivity.
- Stage III (severe): Deep pockets of 6 to 8 mm or more, significant bone loss, loose teeth, pain while chewing, and teeth that visibly shift position.
- Stage IV (advanced): Extensive bone destruction, severe loosening, bite problems, missing teeth, and difficulty eating. At this point, extractions and reconstruction or implants often become necessary.
Why Your Body Turns Against Itself
The bone loss in gum disease isn’t caused directly by bacteria eating through bone. It’s caused by your own immune system. When bacteria breach the gum tissue, your body sends waves of immune cells to fight them. Those immune cells release enzymes and inflammatory signals that break down the connective tissue around your teeth. At the same time, the inflammation activates specialized cells called osteoclasts, whose job is to dissolve bone. Under normal conditions, bone breakdown and bone rebuilding stay balanced. Chronic gum inflammation tips that balance heavily toward destruction: it ramps up bone-dissolving activity while simultaneously suppressing the cells that rebuild bone and even causing those bone-building cells to die off.
One particularly aggressive bacterial species, commonly found in severe gum disease, has evolved remarkable survival tactics. It can invade the cells lining your gums and hide inside them, replicating in a place your immune system can’t easily reach. It also produces enzymes that chop up antibodies, complement proteins, and other immune molecules, essentially disarming your body’s defenses. It can even block the white blood cells that normally rush to infection sites. The result is a chronic, smoldering infection where your immune system causes collateral damage to your own tissues while failing to eliminate the bacteria driving the whole process.
Tooth Loss Is the Biggest Local Consequence
The most direct consequence of untreated gum disease is losing teeth. As the bone around a tooth erodes, the tooth becomes mobile. Research tracking patients over a decade found that tooth mobility is the strongest predictor of tooth loss. Once mobility passes a certain threshold, roughly 60% of those teeth are eventually lost. Molars and teeth with deep pocketing are especially vulnerable.
Tooth loss doesn’t just affect your smile. It changes how you chew, which can limit the foods you eat and affect nutrition. Remaining teeth shift to fill gaps, altering your bite and sometimes causing jaw pain. The jawbone itself continues to shrink in areas where teeth are missing, which can make future dental work like implants more complicated.
Connections to Other Health Problems
Gum disease doesn’t stay contained in your mouth. The same bacteria and inflammatory molecules circulating in diseased gum tissue can enter your bloodstream, and researchers have found significant associations between periodontitis and a range of systemic conditions: cardiovascular disease, stroke, Alzheimer’s disease and dementia, rheumatoid arthritis, obesity, and certain cancers.
The link with diabetes is especially well established and runs in both directions. High blood sugar makes gum infections harder to control, while active gum disease makes blood sugar harder to regulate. This creates a cycle where each condition worsens the other.
For pregnant women, severe gum disease has been associated with preterm birth and low birth weight. One study found that women with generalized periodontitis had up to a sevenfold increased risk of delivering before 32 weeks.
An important caveat: while these associations are strong and consistent across many studies, proving that gum disease directly causes these conditions is a different, higher bar that research hasn’t fully cleared. The American Dental Association has cautioned against claiming that treating gum disease will reduce your risk of heart disease or other systemic conditions without more rigorous evidence. Still, the associations are strong enough that managing gum disease is widely considered part of protecting your overall health.
Who Is Most at Risk
Smoking is the single largest modifiable risk factor. Smokers are roughly four times more likely to develop periodontitis than nonsmokers, and smoking was estimated to be attributable to nearly 75% of periodontitis cases in one large national survey. Even after quitting, the elevated risk of tooth loss persists for years.
Genetics also plays a meaningful role. People who carry certain genetic variations affecting inflammatory signaling have a nearly sevenfold increased risk of developing severe gum disease compared to those without the variation. When heavy smoking and this genetic profile combine, the risk of tooth loss jumps by 7.7 times.
Diabetes, as noted, is both a risk factor and a consequence. Other factors that increase susceptibility include age (prevalence roughly doubles between ages 30 and 65), certain medications that reduce saliva flow, and conditions that suppress the immune system.
Signs You Shouldn’t Ignore
Gum disease can be surprisingly quiet in its early stages, which is part of what makes it dangerous. The symptoms to watch for include gums that bleed when you brush or floss, redness or a purplish color along the gumline, persistent bad breath or an unpleasant taste, soreness or tenderness, gums that are pulling away from your teeth (recession), teeth that feel loose or seem to have shifted, pus along the gumline, and pain when chewing. Many people assume a little bleeding while brushing is normal. It isn’t. Healthy gums don’t bleed.
How Gum Disease Is Treated
The first-line treatment for mild to moderate gum disease is a deep cleaning procedure called scaling and root planing. Your dentist or hygienist numbs your gums with local anesthesia, then uses hand instruments or ultrasonic tools to remove plaque and tartar from your teeth both above and below the gumline. They then smooth the root surfaces so your gums can reattach more easily. There are no incisions or stitches. Antibiotics may be placed directly around the roots or prescribed as pills afterward.
For more advanced cases, referral to a periodontist (a gum specialist) may be needed. Surgical options at that point can include flap surgery to access deeper pockets, bone grafts to rebuild lost support, and tissue grafts to address severe recession.
Regardless of the stage, gum disease requires ongoing management. Once you’ve had periodontitis, you’ll typically need more frequent professional cleanings, often every three to four months rather than the standard six. Your dental team will monitor pocket depths and bone levels to catch any progression early. Combined with thorough daily brushing and flossing, this maintenance can keep the disease stable for years, preserving the teeth and bone you still have.