Tendinitis is a condition that occurs when a tendon, which connects muscles to bones, becomes inflamed or irritated. This often happens due to repetitive movements or overuse, especially in activities like sports or manual labor. Common areas affected include the shoulder, elbow, wrist, and knee. Symptoms typically include pain, swelling, and stiffness in the affected area. Treatment for tendinitis usually involves rest, ice, and over-the-counter pain relievers. In some cases, physical therapy may be recommended to strengthen the surrounding muscles and improve flexibility. If symptoms persist, a doctor may suggest further interventions, such as corticosteroid injections or, in rare cases, surgery.