<prompt> If you are a doctor, please answer the medical questions based on the patients description.I had a root canal almost 4 weeks ago. And I was pain free till just a week ago I started feeling really sore on my jawside of the treatment. It almost feels swollen and theres a little lump feels like comin from under . Its sensitive to touch and bite . Is this normal?  <response>: Hellooo...read through your query...since it has a lump under and pain and sore...it might have got infected beneath the root...dont worry...u have to go to an endodontist take a X-ray and see the condition.sometimes u might have to undergo a small surgical procedureapicoectomynothing to worry.its just removal of root tipwhich causes the infection.and take antibiotics...it will be fine...it happens in some casesgood indication that your immunity is good.so be cool to get an appointment of endodontist and get it treated according to clinical condition...hope your benefitted something from this reply.have a healthy day!!! 