Frozen shoulder, also known as adhesive capsulitis, is a condition characterized by stiffness and pain in your shoulder joint. Signs and symptoms typically begin gradually, worsen over time and then resolve, usually within one or two years. Your risk of developing frozen shoulder increases if you're recovering from a medical condition or procedure that affects the mobility of your arm - such as a stroke or a mastectomy. Treatment for frozen shoulder involves stretching exercises and, sometimes, the injection of corticosteroids and numbing medications into the joint capsule. In a small percentage of cases, surgery may be needed to loosen the joint capsule so that it can move more freely.