<s>[INST] Hello. I have a small painful knot on the inside of my left arm under my bicep. It is slightly swollen in the area and there is some pain under my left arm pit. I lifted a heavy door a week ago but the pain has really increased the last 3 days or so. Any ideas? Thank you. [/INST] Dear Sir/MadamI have gone through your query and read your symptoms.In my opinion, if this has resulted after lifting weight than there are chances of biceps tear, in that case it will move as the muscle contacts, you should see your doctor and get ascertained in thisI hope that answers your query. If you want any more clarification, contact me back.ThanksDr Narender Saini </s>