Tendinitis

Tendinitis is the inflammation or irritation of a tendon — the thick, fibrous cords that attach muscles to bones. Tendons are essential for movement: when a muscle contracts, it pulls on its tendon, which in turn moves the bone. Tendinitis occurs when a tendon is overused, subjected to repetitive motions, or sustains a sudden injury, causing pain, tenderness, and mild swelling near the affected joint.

The condition can affect any tendon in the body but is most common in the shoulders (rotator cuff tendinitis), elbows (tennis elbow and golfer's elbow), wrists, knees (patellar tendinitis or jumper's knee), and Achilles tendon (the large tendon connecting the calf muscle to the heel). Tendinitis is particularly common in athletes, manual laborers, and people whose jobs or hobbies involve repetitive motions.

Modern understanding distinguishes between acute tendinitis (true inflammation, typically from a recent injury or overuse) and chronic tendinopathy (a degenerative condition where the tendon structure breaks down over time without necessarily involving active inflammation). This distinction is clinically important because the treatment approach differs — anti-inflammatory treatments are most effective for acute tendinitis, while chronic tendinopathy often responds better to progressive loading exercises that stimulate tendon repair and remodeling.

If you're experiencing pain near a joint that worsens with movement and is tender to the touch, tendinitis may be the cause. Early treatment is important because continuing to stress an inflamed tendon can lead to chronic tendinopathy or even tendon rupture, both of which are more difficult to treat.

For active individuals, understanding proper warm-up techniques, progressive training principles, and the importance of recovery days can help prevent tendinitis. If you develop tendon pain, reduce the aggravating activity, apply the RICE protocol, and see a healthcare provider if symptoms persist beyond 1-2 weeks or interfere with daily activities.