Tendonitis is often caused by an acute injury, such as when an athlete lands a jump the wrong way. The injury puts excessive force on a tendon and leaves it with tiny tears that cause inflammation.
Tendonosis is typically caused by overuse or repeated injuries over time. For example, when you overuse a tendon without giving it enough time to rest and heal. As opposed to tears forming in the tendon, it involves the actual tissue of the tendon degrading, giving it a hard, thick, and scarred appearance.
In addition, there are several other risk factors that affect your chance of developing tendonosis:
- Ageing
- Certain diseases like rheumatoid arthritis and gout
- Irregular physical activity, such as playing sports only on the weekends