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What Is Tendinitis?

Tendinitis is an inflammation in or around a tendon, a band of fibrous tissue that connects a muscle to a bone and transmits the force the muscle exerts. Tendons are designed to withstand bending, stretching and twisting, but they can become inflamed because of overuse, disease or injuries that leave them with torn fibers or other damage. The pain can be significant and worsens if damage progresses because of continued use of the joint. Most tendinitis heals in about two weeks, but chronic tendinitis can take more than six weeks, often because the sufferer doesn't give the tendon time to heal. Diseases such as diabetes, arthritis and gout can slow healing.

What Causes It?

Tendons can become inflamed when overstressed from any activity. Weekend athletes, who exercise sporadically rather than regularly, are often laid low by sore tendons. But by far the most common cause is repetitive stress — using the same joints for the same stressful movements again and again. This happens not only in sports but also in many types of office work and other situations. Tendons are also more likely to become inflamed with increasing age since muscles and tendons tend to lose their elasticity over time.