Gum bulge may be caused by chronic gingivitis, pubertal gingivitis, pregnancy gingivitis, etc. as follows. 1. Chronic gingivitis: usually caused by plaque. When suffering from chronic gingivitis, the surface of the gingiva is shiny, the tissue is edematous, the gingival margin is thickened, the gingival papillae become rounded and hypertrophied, and bulbous hyperplasia may appear, even covering part of the tooth surface. 2. Adolescent gingivitis: plaque is the main cause of its etiology, and at the same time affected by the hormone level changes during puberty. It is often manifested as obvious swelling of lipside gingiva, soft texture of gingiva, and obvious bleeding on probing. 3. Gingivitis during pregnancy: women during pregnancy, female hormone levels rise, resulting in the original chronic inflammation of the gums aggravated, the gums occurred significant inflammatory swelling or gingival tumor-like changes. Gum bulge may have other reasons, some systemic diseases can also appear gum swelling and bleeding, it is recommended to go to the hospital in time, clear cause for targeted treatment.