Under normal circumstances, no active bleeding after tooth extraction, then lying flat or lying on the side can be, if there is bleeding after tooth extraction, you should try to choose the side of the lying, as follows. 1. No active bleeding: usually about 15~30 minutes after tooth extraction, bleeding will stop, blood clot will be formed, and the extraction wound will start to heal, at this time, lying down or lying on the side of the healing of the extraction wound and the general health does not have a greater impact. 2. Bleeding after tooth extraction: If bleeding does not stop after tooth extraction or secondary bleeding is caused by infection, you should choose to lie on your side to prevent blood from flowing into the trachea due to gravity, causing suffocation. If the above symptoms occur, it is recommended to go to the hospital in time, with the help of the doctor to clarify the cause and carry out targeted treatment.