Bleeding, redness, and painful or sore gums can be a symptom of gingivitis (inflammation of the gums) that arises due to a number of different causes. Bleeding of the gums is sometimes referred to as gingival bleeding, and it may occur during brushing or flossing. The soreness can be accompanied by swelling of the gum tissues. Most commonly, gingivitis is the result of plaque buildup on the teeth around the gum line. Without adequate removal, the plaque hardens to become tartar, which worsens gingivitis and can, over time, lead to receding gums and even damage the bones of the jaws. Bleeding from the gums, particularly when accompanied by easy bruising and/or bleeding at other sites in the body, can also be caused by diseases that interfere with the normal blood-clotting process. Blood-thinner medications are another potential cause of bleeding gums. The hormonal changes during pregnancy can also increase the sensitivity of the gums, which may lead to increased bleeding in some cases. Those with chronic conditions that affect the function of the immune system, such as HIV infection or diabetes, may also have an increased tendency to develop gingivitis.