Bleeding gums are a symptom of gingivitis (inflammation of the gums).
Most commonly, gingivitis is the result of plaque (film of bacteria) build-up on the teeth and around the gum line. Without adequate removal, the plaque hardens to become tartar, which worsens gingivitis and can, over time, even damage the bones of the jaws. The hormonal changes of pregnancy also increases the sensitivity of the gums, which may lead to increased bleeding in some cases. People having habit of tobacco chewing, betel (paan) chewing,etc have increased tendency to gum diseases. Those with serious medical conditions such as leukemia, HIV infection, diabetes, bleeding or platelet disorders may also have an increased tendency to develop gingivitis.