Frozen shoulder (also known as adhesive capsulitis) describes a condition in which the articular capsule that surrounds the ball-and-socket glenohumeral joint of the shoulder swells and becomes stiff.
Frozen shoulder differs from shoulder impingement syndrome in that the stiffness and joint pain will progress until shoulder motion is extremely difficult, effectively freezing the joint.
Fortunately, frozen shoulder does improve with time and the stiffness and loss of motion will subside, although it may take up to 3 years. Non-surgical treatment for frozen shoulder involves NSAIDs and physical therapy with a focus on shoulder stretching exercises. Surgical treatments such as arthroscopy are options when physical therapy and medication are not effective.