Bleeding gums may be caused by periodontitis, but also may be related to mechanical injury, gingivitis, vitamin deficiency, systemic diseases, etc., and should be clarified after timely consultation. 1. Mechanical injury: such as improper brushing, flossing, etc., leading to mechanical damage to the gums, can also lead to bleeding teeth. 2. Gingivitis: including adolescent gingivitis, pregnancy gingivitis, chronic gingivitis, etc., can lead to bleeding gums, and should be clearly diagnosed after consultation. 3. Periodontitis: it is a common disease that can lead to bleeding teeth, the cause of which is mainly related to dental plaque, when the bacterial virulence in plaque is too strong, tartar stimulation, etc., it will lead to redness, swelling, bleeding and other manifestations of the gums, and gingivitis is also easy to progress to periodontitis. 4. Vitamin deficiencies: Vitamin C and K deficiencies can cause the gums to bleed easily. 5. Systemic diseases: such as neutropenia, leukemia, aplastic anemia, hemophilia, diabetes and other diseases, can also lead to bleeding gums. Bleeding gums, need to actively seek medical attention, clear cause for targeted treatment.