Peter Attia· MD
A tendonitis is just inflammation in the tendon and if it's beginning to wear and tear and degenerate you'll get some longitudinal fissuring in those those collagen fibers and then it fills in with some inflammatory tissue and then that can envelop the tendon and so you're getting kind of er constant rubbing and further degeneration of that you get chronic pain you can inject it with cortisone but then ultimately they can rupture