Tendonitis (which is also sometimes spelled tendinitis) is a form of painful inflammation in the tendons, which are the chord-like parts of the body that connect muscles to bones. Usually caused by repetitive movements (like exercise or sitting in the same position for many hours), injuries or built-up inflammation over time, tendonitis can cause a lot of pain.

People who are over 40 years old tend to get tendonitis more than younger people, but really anyone can develop symptoms depending on how damaged versus elastic tendons become. It’s true that as we age, our ligaments, bones and tendons slowly weaken with everyday wear and tear, so we’re more likely to experience things like muscle or joint pain. Tendonitis comes down to experiencing inflamed tendons that are more susceptible to stress, strain, movement and tears. Despite what most people assume, this can affect people of all ages, sizes and physical activity levels, not just serious athletes or the elderly.