Gum disease is an infection of the tissues that hold your teeth in place, and it affects roughly 42% of American adults over age 30. It starts as mild inflammation of the gums (gingivitis) and, if left untreated, can progress to a more serious condition called periodontitis, which damages the bone and connective tissue anchoring your teeth. Most people don’t realize they have it because the early stages are painless.
Gingivitis vs. Periodontitis
Gum disease exists on a spectrum with two main stages. Gingivitis is the early, reversible form. The hallmark signs are red, swollen gums that bleed when you brush or floss, and sometimes bleed for no obvious reason at all. Because gingivitis rarely hurts, it often goes unnoticed for months or even years.
Periodontitis is what happens when gingivitis isn’t addressed. The inflammation spreads from the gum surface deeper into the structures that support your teeth: the ligaments and the jawbone itself. As the gums pull away from the teeth, gaps called periodontal pockets form between the tooth and gum line. In healthy gums, these pockets measure 1 to 3 millimeters. Pockets of 4 to 5 millimeters indicate moderate disease, and anything 6 millimeters or deeper signals severe periodontitis. Over time, the bone around the teeth breaks down, teeth shift position, become loose, and may eventually need to be removed.
How It Develops
The process begins with plaque, the sticky film of bacteria that naturally forms on your teeth throughout the day. When plaque isn’t removed regularly, these bacterial communities mature and trigger your immune system to respond. In a healthy mouth, that immune response is proportional and controlled. In people susceptible to gum disease, the response becomes excessive. Your own immune cells release inflammatory compounds that, in high concentrations, start destroying the surrounding soft tissue and bone rather than protecting it.
This is what makes gum disease counterintuitive: much of the actual damage isn’t caused directly by bacteria. It’s caused by your body’s overreaction to those bacteria. The bacterial buildup is the trigger, but the tissue destruction is largely self-inflicted at a cellular level.
What It Feels Like at Each Stage
Early gingivitis is subtle. You might notice a pink tinge on your toothbrush or a little blood when you spit after brushing. Your gums may look slightly puffy or darker red than usual, especially along the gum line. There’s no pain, so most people dismiss it.
As gum disease advances into periodontitis, the signs become harder to ignore. Your gums may feel tender or sore. You might develop persistent bad breath that doesn’t go away with mouthwash. Teeth can become sensitive, particularly near the gum line, as receding gums expose parts of the tooth root that were previously covered. Your teeth may look longer than they used to. In advanced stages, you’ll notice teeth shifting, feeling loose, or pain when chewing. By the time these symptoms appear, significant bone loss has often already occurred.
Who Is Most at Risk
Smoking is the single largest modifiable risk factor for gum disease. Studies consistently find that smokers face between 2.5 and 6 times the risk of developing periodontitis compared to nonsmokers. There’s a clear dose-response relationship: the more you smoke and the longer you’ve smoked, the more severe the disease tends to be. One population-based study found that heavy smokers had nearly seven times the odds of significant tissue loss compared to the least-affected group.
Genetics also play a role, though their influence is most pronounced in combination with environmental factors like smoking. Certain gene variations affect how aggressively your immune system responds to bacterial buildup. Interestingly, in nonsmokers, the impact of these genetic differences is mostly negligible. It’s the combination of genetic susceptibility and smoking that dramatically amplifies risk.
Other significant risk factors include diabetes, age, and poor oral hygiene. Adults 65 and older are hit hardest: nearly 60% have some form of periodontitis. Men are more commonly affected than women, and lower socioeconomic status is associated with higher rates, likely reflecting differences in access to dental care and preventive education.
The Link to Diabetes and Other Conditions
The relationship between gum disease and diabetes runs in both directions. Chronic gum inflammation can worsen insulin resistance, making blood sugar harder to control. At the same time, people with diabetes are more susceptible to developing gum disease in the first place because elevated blood sugar impairs the body’s ability to fight infections, including those in the gums. Research shows a moderate but statistically significant association between periodontitis and diabetes, and treating gum disease can improve blood sugar management.
Links to cardiovascular disease and rheumatoid arthritis have also been studied, though the evidence for those connections is weaker. The underlying theory is that chronic oral inflammation can contribute to systemic inflammation throughout the body, but the strength of those associations is still being clarified.
How Dentists Diagnose It
During a dental exam, your dentist or hygienist uses a small probe to measure the depth of the pockets between your gums and teeth. Healthy pockets are 1 to 3 millimeters deep with no bleeding. Pockets of 4 to 5 millimeters with bleeding suggest moderate disease, while pockets 6 millimeters or deeper indicate severe periodontitis. X-rays reveal whether bone loss has occurred around the roots of your teeth.
Periodontists classify the disease into four stages (I through IV) based on how much bone and tissue has been lost, whether teeth have already been lost to the disease, and how complex treatment would be. They also assign a grade (A, B, or C) reflecting how quickly the disease is progressing: slow, moderate, or rapid. This staging system helps determine how aggressive treatment needs to be.
Treatment and What to Expect
Gingivitis is fully reversible with improved oral hygiene and professional cleaning. If caught early, no lasting damage occurs.
For periodontitis, the standard first-line treatment is a deep cleaning procedure where your dentist or hygienist cleans below the gum line, removing hardened plaque from the tooth roots and smoothing rough spots where bacteria tend to collect. This is typically done in sections over two or more visits, often with local numbing. The goal is to reduce pocket depths and allow the gums to reattach more closely to the teeth. Deep pockets of 5 millimeters or more, especially on teeth with complex root anatomy, are harder to clean effectively and require considerable skill.
After treatment, you’ll need regular maintenance visits, typically every three to four months rather than the standard six-month schedule. If pockets remain deep and inflamed after deep cleaning, surgical options exist to access and clean the roots more thoroughly, rebuild lost bone, or reshape the gum tissue.
Prevention That Actually Works
Brushing twice a day removes plaque from the surfaces of your teeth, but a toothbrush can’t reach the tight spaces between teeth where gum disease often begins. Adding interdental cleaning, whether with floss or small interdental brushes, makes a measurable difference. A meta-analysis found that using interdental brushes alongside regular brushing reduced gum inflammation by 34% and plaque levels by 32% compared to brushing alone.
If you smoke, quitting is the most impactful thing you can do for your gum health. Regular dental visits allow early detection before symptoms appear, which is critical because by the time gum disease causes noticeable problems, reversible gingivitis has often already progressed to irreversible periodontitis. Managing blood sugar levels matters too, especially if you have diabetes or prediabetes, given the two-way relationship between gum disease and glycemic control.