牙龈病（gingival diseases）是指一种发生于牙龈组织的疾病，牙龈病病损范围限于牙龈，而不累计牙槽骨、牙周膜和牙骨质。牙龈病主要包括牙龈炎性损害和牙龈增生。

牙龈病一般不侵犯深层牙周组织，是口腔疾病中的常见病和多发病。细菌集在牙龈和牙齿中间的空穴中，引起出血、发炎、感染和潜在的提前掉牙。牙龈炎症一般由牙菌斑引起，牙菌斑最初在压面形成时，主要为因伤菌斑。当堆积时间长了菌斑就会引起牙龈炎症，使牙龈沟加深、龈沟液增多，逐渐地菌斑会向龈下延伸发展，形成龈下菌斑。对牙周环境造成更大的威胁。

Gingivitis ("inflammation of the gum tissue") is a non-destructive periodontal disease. The most common form of gingivitis, and the most common form of periodontal disease overall, is in response to bacterial biofilms (also called plaque) adherent to tooth surfaces, termed plaque-induced gingivitis. Gingivitis is reversible with good oral hygiene. However, in the absence of treatment, or if not controlled, gingivitis can progress to periodontitis, where the inflammation results in tissue destruction and alveolar bone resorption, which can ultimately lead to tooth loss.