Bursitis: The Inflammation That Sits Just Outside the Joint
Bursae are small fluid-filled sacs that cushion the space between bone and soft tissue. When one gets inflamed, a condition called bursitis, the pain lands directly over the joint and feels indistinguishable from arthritis to most people. The shoulder, hip, and knee are the most common sites. A 2017 review published in the American Family Physician estimated that bursitis accounts for nearly 0.4% of all primary care consultations, and a significant portion of those patients initially present believing they have arthritis.
