Tendonitis is a condition that occurs when the cords of tissue responsible for connecting muscles to bones become inflamed. If you’re experiencing pain in your tendons that gets worse when you move or engage in physical activity, you may have tendonitis. Other signs of tendonitis include: - Joint pain - Redness - Warmth - Swelling from fluid - Crackling sensations - Difficulty moving - A grating feeling in the joints These symptoms can occur in areas of your shoulders, elbows, and knees. If you experience sudden and severe joint pain, there is a chance you could have ruptured your tendon. In severe cases, you may hear snapping or popping sounds. If your doctors suspect you have tendonitis, they will run a series of tests. They will conduct a physical examination of the injured area, ask you a few questions, perform a joint aspiration, and/or take you to get X-rays.