Bleeding gums is usually a sign of gum disease. In the great majority of cases it is a sign of a condition called gingivitis, which just means inflammation of the gums. If gingivitis is not held in check, then it can develop into a more serious condition called periodontal disease. If left untreated, periodontal disease can result in teeth falling out. Most people will experience some sort of gum disease in their lifetime.  This is largely the result of western diets which are high in sugar. Sugary food encourages the growth of bacteria (plaque) on the teeth, which leads to gum disease.