What Causes Swollen Gums?

Gingival swelling—also known as gingival enlargement or gingival hyperplasia—is a common clinical finding characterized by an abnormal increase in the size of gum tissue. It is not a disease in itself but rather a sign of underlying pathology, and its causes fall into several broad categories: inflammatory, drug-induced, systemic, and neoplastic.

Inflammatory gingival enlargement is the most frequent cause and typically results from chronic plaque accumulation along the gingival margin. Poor oral hygiene leads to bacterial biofilm formation, triggering an immune-mediated inflammatory response. This manifests as redness, edema, bleeding on probing, and soft, spongy gingival tissue—classic features of gingivitis. If left untreated, it may progress to periodontitis with attachment loss and bone destruction.

Drug-induced gingival overgrowth is another well-documented etiology, particularly associated with calcium channel blockers (e.g., nifedipine, amlodipine), anticonvulsants (e.g., phenytoin), and immunosuppressants (e.g., cyclosporine). The mechanism involves fibroblast proliferation and excessive collagen deposition, often exacerbated by pre-existing inflammation. Notably, the degree of enlargement correlates with both drug exposure and local plaque burden.

Systemic conditions can also contribute to gingival swelling. These include hormonal fluctuations during pregnancy or puberty, uncontrolled diabetes mellitus (which impairs neutrophil function and wound healing), and hematologic disorders such as leukemia—where gingival infiltration by malignant white blood cells produces firm, purplish, and sometimes ulcerated enlargements.

Rarely, gingival swelling may signal a benign or malignant neoplasm—for example, pyogenic granuloma (a reactive vascular lesion), peripheral giant cell granuloma, or oral squamous cell carcinoma. Any persistent, asymmetric, ulcerated, or rapidly growing lesion warrants biopsy for definitive diagnosis.

Accurate diagnosis requires a comprehensive evaluation: detailed medical and medication history, clinical periodontal assessment, radiographic imaging when indicated, and, in atypical cases, histopathologic examination. Management is etiology-specific—emphasizing plaque control and professional debridement for inflammatory causes; dose adjustment or alternative medications for drug-induced cases; and coordinated care with relevant specialists for systemic or neoplastic contributors.