Gingivitis is most often the underlying cause of bleeding gums. This occurs when the gums are inflammed due to bacteria that forms around the area where the tooth and gum meet. Gingivitis is a manageable condition that can be treated by your dentist. Periodontitis, however, is a more advanced form of gum disease that is irreversable and bleeding can also be a symptom of this. It attacks the root surface and the bone of the tooth and is a very painful condition to live with. With regular visits to your dentist and with thorough oral hygiene care, the progession can be halted. In cases where the periodontitis is too advanced, you will need to be referred for specialist care.