Seeing blood when you brush your teeth is often a signal that something is wrong with your gums and that you have a buildup of plaque. Dentists recommend brushing and flossing twice a day, and it is never too late to start. If regular brushing and flossing do not seem to help reduce or eliminate the bleeding in your gums, you should make an appointment with your local dentist. Notify your dentist that your gums are bleeding and that you might need a deep cleaning or a scaling to correct the issue.