###Human: During second sitting of RCT, the canal is bleeding. Why? ###Assistant: Hi. Thanks for the query. In case if the canals are bleeding, then there is a possibility that the dentist is good too deep beyond the root tips causing bleeding or the infection has not yet subsided. So, first of all, your dentist can fill the canals with Calcium hydroxide and leave it for a week. It is an antibacterial and will help in resolving the infection and will ease in filling of the root canals. Along with it, you can also be advised a course of oral antibiotics for fixing the infection. Please send me the scan of your x-ray so that I can have a look and advise you how to proceed further towards most appropriate treatment. Also, please tell that is there any pain present in the tooth on chewing or spontaneously too. Please revert back with answers for further help. Regards.