If you do not take care of your gums (Box), you can develop gum disease. Gum disease can develop when a thin layer of bacteria, called plaque, is allowed to collect along the gumline and between the teeth. This can cause your gums to swell and bleed and, if left untreated, can even cause tooth loss. There are mild forms of gum disease that may be reversed if caught early and more severe forms that involve specialized treatment from a dentist.