A very hard bump on the root of the tooth may be a normal phenomenon, or it may be alveolar bone hyperplasia, periodontal abscess, apical fistula and other diseases related. 1. Normal phenomenon: the gum layer is relatively thin, the structure of the root of the tooth is obvious, part of the elderly, lack of nutrition, you can clearly see the root of the tooth is very hard bump, the root of the tooth at the gums and there is no abnormality. 2. Alveolar bone hyperplasia: Alveolar bone hyperplasia is mainly manifested as hard bone plate in the jawbone area, which bulges outward, and looks like the root of the tooth has a very hard bulge like the bone. 3. Periodontal abscess: when suffering from periodontal abscess, there is swelling of the gums, which can be manifested in the roots of the teeth appear like bone-like bumps, at this time, touching the bumps with your hand, you can also feel the sense of fluctuation, and even there is a foul-smelling liquid outflow. 4. apical fistula: apical fistula will also lead to the patient’s gums appear obviously swollen, its texture is hard, visually looks like the root of the tooth is very hard bump, at this time the affected area there is pain, redness and swelling and other discomforts. When you can’t tell if the root of the tooth is hard and bumpy, you can go to the regular dental hospital in time.