There are many reasons why teeth bleed when sucked, common causes are dental calculus, gingivitis, thrombocytopenia, etc., for which the treatment methods are cleaning oral calculus, anti-infection treatment of gums, and platelet boosting treatment. 1. The existence of dental calculus will lead to loosening between the tooth root and gums, teeth will bleed when sucked, you can go to the stomatology department for dental calculus cleaning, so that the tooth root and gums are relatively strong, to avoid the bleeding phenomenon. 2. Gingivitis, the gum fibrous tissue in a long-term inflammatory state, blood vessels around the gums are congested, a stimulus or a suction may appear bleeding gums. You can go to the stomatology department for anti-infection treatment for gingivitis. 3. Thrombocytopenia often occurs when the gums bleed or nosebleed and other symptoms, it is recommended to go to the hospital for routine blood tests to see if there is thrombocytopenia. If thrombocytopenia is recommended to enhance the treatment of platelets, platelet transfusion can also be chosen when there is a serious lack of platelets. There are other causes and treatments for teeth once sucked, it is recommended to go to stomatology or related departments in time to identify the cause of the disease and give targeted treatment. The above medication should be used under the guidance of a doctor.