Overuse tendinopathies are a common cause of pain and disability in athletes. According to histological findings, it is a failed healing response to overuse tendon injury. In obesity, macrophages and mast cells migrate to adipose tissue, and the resulting decreased availability of immune circulating cells should be responsible for less effective immune responses to acute tendon injury. In diabetic patients, free glucose molecules attach to collagen, alter collagen solubility, increase resistance to enzymatic degradation, and impair cross linking, contributing to the subsequent development of chronic tendinopathy secondary to a failed healing response to a tendon insult. Prolonged systemic, low-grade inflammation and impaired insulin sensitivity act as a risk factor for a failed healing response after an acute tendon insult, and predispose to the development of chronic overuse tendinopathies. Further studies may reveal novel therapeutic treatment approaches.