What physiological process often leads to frozen shoulder?

Frozen shoulder, also known as adhesive capsulitis, is primarily characterized by the inflammation of the joint capsule surrounding the shoulder. This inflammation leads to a thickening and tightening of the capsule, resulting in restricted mobility and pain. The condition typically develops gradually and can significantly affect a person's range of motion, making everyday activities difficult.

The inflammatory response is a key component in the development of frozen shoulder, as it triggers a cascade of events that can lead to the formation of adhesions within the shoulder joint itself. These adhesions further contribute to the loss of range of motion and can cause significant discomfort.

In contrast, the other options focus on processes not typically associated with the onset of frozen shoulder. Excessive fluid might be involved in certain shoulder conditions, but it is not the primary cause of frozen shoulder. Muscle spasms may occur as a secondary reaction to pain or limited movement, and cartilage deterioration relates more to osteoarthritis and not directly to the underlying mechanisms responsible for frozen shoulder. Understanding the dominant role of joint capsule inflammation is crucial in grasping the physiological basis for this condition.