How can i treat tendonitis of the thumb?

Rest, ice...: Although most tendonopathies can be helped with rest, ice, and splinting (such as a preformed thumb-spica splint available at many drug stores), occasionally physical therapy, phoresis, or even injections can be benficial.

Diagnosis first: Make sure you have the proper diagnosis first as often there can be other issues such as arthritis stresssfracture or other issues that can confound such as nerve irritation, proper splinting if needed. Nsaids. Ice rest stretching and other modalities can help such as an injection in that region. Common tendon issues thumb are triggering, dequervains and intersection syndrome, but arthritis 2.

Many Possibilities: Prolotherapy typically by itself will cause ligaments to tighten up, usually due to scarring or fibrosis of the ligaments. However now prolotherapy is used to introduce new blood supply to the area and then many times following it with the prp and/or stem cells in the area can repair the tissue/ligaments by the hopes that the stem cells regenerate the same normal tissue type. Regenexx.Com

Tenditis: You need to see a hand surgeon or a rheumatologist. You may need an injection of cortisone and a splint.