What causes swollen and bleeding gums?

Swollen and bleeding gums may be gingivitis, periodontitis, leukemia and so on.
1. Gingivitis: It is caused by bacterial infection. The oral cavity is a bacterial environment, some bacteria attached to the plaque or tartar in the neck of the teeth, the use of food debris attached to the neck of the teeth and soft tartar decomposition to produce some toxins or enzymes to stimulate the gums, which can lead to the symptoms of swollen and bleeding gums.
2. Periodontitis: a disease of the soft tissues around the teeth, caused by plaque acting on the surface of the teeth and stimulating the periodontal tissues. The main symptoms of periodontitis include inflammation of the gums, such as red and swollen gums, bleeding gums, and gum recession.
3. Leukemia: Bleeding due to thrombocytopenia is common when leukemia occurs. Bleeding can occur in all parts of the body, and the most common site of bleeding is the skin. Bleeding spots, petechiae, ecchymosis of the skin, nosebleeds and bleeding gums can occur and are also common. Sometimes patients may have bleeding and swollen gums when brushing their teeth.
There may be other causes of swollen and bleeding gums, and you should visit your doctor to identify the exact cause and treat accordingly if necessary.