I believe i may have tendonitis, is it best to see a medical doctor or physical therapist?

Medical doctor: Consult a medical doctor first for exam and establish diagnosis. Physical therapy is commonly part of treatment plan.

It all depends.: One would need to know more about the "tendinitis". Inflammation caused by an injury would probably be best evaluated by a physician first. In all likely hood, he will direct you to a physical therapist if necessary. I would be okay if a patient sought treatment from a therapist for inflammation of a non-traumatic origination. Mild inflammation can easily be treated with NSAID, ice and /or heat.