Tendinitis is inflammation of a tendon , the thick cord that attaches muscle to bone. Tendinitis often results from overuse sports injuries or repetitive movements, but it can also occur from biomechanical problems, metabolic conditions such as diabetes, or even different types of arthritis. Some types of tendinitis can occur suddenly, last for days or longer, and usually get better with rest or treatment. It is important to see a foot and ankle surgeon to evaluate your tendinitis, because without proper treatment, tendinitis can lead to tendonosis, damage to the tendon substance itself. When tendonosis occurs, it can eventually result in tendon rupture, which may necessitate surgery. Luckily, most of the time tendinitis resolves with rest and conservative treatment. When tendinitis persists, and calcium deposits are present, treatments like Extracorporeal Shock Wave Therapy (ESWT) can be used, as an alternative to surgical removal, to help break up these deposits, relieve pain, and enhance healing.