Bleeding gums and painful gums can be caused by a number of factors. Improperly fitted dentures and aggressive tooth brushing can cause the gums to become sore. Sore gums can also be caused by an allergic reaction or certain disease processes like anemia. Being malnourished is a major cause of gum pain. Infections like gingivitis and periodontitis can also cause the gums to become sore. When you are suffering from gum pain, you may also have these symptoms.