The most common cause of bleeding from brushing is periodontal disease. When there is periodontal disease, the gums are edematous, the gums are filled with a large number of new blood vessels and expand, the permeability is enhanced, they become brittle, and they bleed easily when they are touched or sucked. In some patients, blood clots appear in the mouth in the morning. Some patients may have problems with blood clotting when they brush their teeth. When periodontal disease progresses further, deep pockets appear around the teeth and the gums swell with pus overflow. The resorption of the supporting bone around the tooth increases and the tooth becomes loose. Therefore, if you find your toothbrush stains red when you brush your teeth, or if there is blood on the surface of food when you eat hard foods such as apples, it is time to go to the periodontal department at the hospital for specialist and blood tests and early treatment.