By Lois Zoppi, BAReviewed by Jennifer Logan, MD, MPH Tendonitis and bursitis are common conditions that cause swelling and pain around muscles and bones. Both conditions often occur in the shoulders, elbows, wrists, hips, knees, and ankles. Although tendonitis and bursitis present similar symptoms, they are two distinct conditions affecting different parts of the body. What is Tendonitis? A tendon is a flexible...