My appendix scar i've had for 10 years still hurts sometimes especially when i go run why is that? it doesn't swell or anything it feel like a strain.

Adhesions/blockage: It is possible your scar is attached on the inside to omentum and/or bowel, so when you run (shakes the adhesion and attached omentum) you feel a pulling sensation. As long as you are without fever or vomiting, it is okay to continue.

Scar tissue: You may have some scar tissue around one of the sensory nerves. Consider seeing a pain management physician trained in injection therapy to see if this may be an option for you.