There is also a lack of synovial fluid, which normally lubricates the gap between the arm bone and socket to help the shoulder joint move. It is this restricted space between the capsule and ball of the humerus that distinguishes adhesive capsulitis from a less complicated painful, stiff shoulder. There are a number of risk factors for frozen shoulder, including diabetes, stroke, accidents, lung disease, and heart disease. The condition rarely appears in people under 40 years old. With a frozen shoulder, the joint becomes so tight and stiff that it is nearly impossible to carry out simple movements, such as raising the arm.
People complain that the stiffness and discomfort worsens at night.
A doctor may suspect the patient has a frozen shoulder if a physical examination reveals limited shoulder movement. An arthrogram may confirm the diagnosis. Treatment of this disorder focuses on restoring joint movement and reducing shoulder pain. Usually, treatment begins with nonsteroidal anti-inflammatory drugs and the application of heat, followed by gentle stretching exercises. These stretching exercises, which may be performed in the home with the help of a therapist, are the treatment of choice.