Impaired tendon function leads to pain and restricted movement of the joints. This impairment can be due to the degeneration of the tendon and, in the worst-case, due to rupture. Conservative and surgical treatments are available, however treatment duration can be long and the failure rate is high. In order to develop new treatment strategies, a better understanding of the processes underlying tendon alterations as well as the factors influencing them is necessary. This talk will give insights into the process of tendon degeneration and biology obtained from human tissue samples and animal studies.