| Milder stage | Gingivitis (reversible with treatment) (American Dental Association) |
| Advanced stage | Periodontitis (manageable, not fully reversible) (American Academy of Periodontology) |
| Leading cause of adult tooth loss | Periodontal (gum) disease (American Academy of Periodontology) |
| Primary cause | Bacterial plaque buildup along and below the gumline |
| Key risk factors | Smoking, diabetes, poor oral hygiene, genetic predisposition |
| Most common early symptom | Bleeding gums during brushing or flossing |
The Two Main Stages of Gum Disease
Gum disease — clinically called periodontal disease — progresses through two recognized stages, each with distinct characteristics and treatment needs.
| Milder stage | Gingivitis (reversible with treatment) (American Dental Association) |
| Advanced stage | Periodontitis (manageable, not fully reversible) (American Academy of Periodontology) |
| Leading cause of adult tooth loss | Periodontal (gum) disease (American Academy of Periodontology) |
| Primary cause | Bacterial plaque buildup along and below the gumline |
| Key risk factors | Smoking, diabetes, poor oral hygiene, genetic predisposition |
| Most common early symptom | Bleeding gums during brushing or flossing |
Gingivitis
Gingivitis is the earlier, milder stage. It occurs when plaque (a sticky film of bacteria) accumulates along the gumline and triggers inflammation. At this stage, damage is confined to the gum tissue itself — the bone and connective tissue anchoring teeth remain intact. Crucially, gingivitis is reversible with consistent at-home hygiene and professional cleaning.
Periodontitis
When gingivitis goes unaddressed, it can advance to periodontitis. Here, the bacterial infection spreads below the gumline. The body's inflammatory response begins breaking down the bone and ligaments supporting teeth. Pockets form between gum and tooth, deepening over time and becoming harder to clean. Periodontitis cannot be fully reversed, but it can be controlled with professional treatment. See our overview of scaling and root planing for details on the standard first-line treatment.
Warning Signs to Know
Gum disease is often painless in its early stages, which is why many adults don't notice it until significant damage has occurred. Common symptoms include:
- Bleeding gums when brushing or flossing — the most common early sign
- Gums that appear red, swollen, or tender rather than pale pink and firm
- Persistent bad breath not explained by food or dry mouth
- Gums that are pulling away from teeth, making teeth look longer
- Tooth sensitivity due to exposed root surfaces
- Loose or shifting teeth in later-stage disease
- Visible pus between teeth and gums
If you notice any of these signs, scheduling a dental evaluation promptly is the most important next step. Early detection makes a significant difference in outcomes.
Gingivitis
The early, reversible stage of gum disease characterized by inflammation of the gum tissue due to plaque buildup. Bone and tooth-supporting structures are not yet damaged at this stage.
Periodontitis
The advanced stage of gum disease in which infection spreads below the gumline, destroying the bone and connective tissue that hold teeth in place. It cannot be fully reversed but can be managed with professional care.
Periodontal Pocket
A deepened gap between the gum and tooth that forms as gum disease progresses. Deeper pockets harbor more bacteria and are harder to clean, accelerating tissue and bone loss.
Plaque
A sticky, colorless film of bacteria that forms continuously on tooth surfaces. If not removed by brushing and flossing, it hardens into tartar and drives gum inflammation.
Tartar (Calculus)
Hardened plaque that has mineralized on tooth surfaces. Tartar cannot be removed by brushing alone and requires professional dental cleaning to eliminate.
What Happens When Gum Disease Goes Untreated
Without treatment, periodontitis progresses along a predictable path — and the consequences extend well beyond the mouth.
Tooth Loss
As supporting bone erodes, teeth lose their structural foundation. Advanced periodontitis is the leading cause of tooth loss in adults, according to the American Academy of Periodontology. Unlike cavities, which destroy a tooth from within, gum disease dismantles the architecture holding teeth in place.
Systemic Health Connections
Research has associated severe gum disease with a higher risk of certain systemic conditions, including cardiovascular disease and complications in people managing diabetes. The relationship is complex and still being studied — gum disease doesn't cause these conditions directly, but chronic oral inflammation may interact with broader inflammatory processes in the body. People with diabetes, in particular, should be aware that poorly controlled blood sugar can worsen gum disease, and gum disease may make blood sugar harder to manage.
Spread of Infection
Oral bacteria can enter the bloodstream through inflamed gum tissue. In rare but serious cases — particularly in people who are immunocompromised — this can contribute to infections elsewhere in the body. For a related perspective on dental infections that require urgent attention, see our article on what a tooth abscess involves and when it becomes urgent.
For a broader framework on keeping gums and teeth healthy throughout adulthood, the complete adult oral health guide is a useful reference. And if you want to audit your current daily habits for gaps, our oral health habits checklist walks through the key risk factors.
This article is for general informational purposes only and does not constitute medical or dental advice. Always consult a licensed dental professional for evaluation, diagnosis, and personalized treatment recommendations.