Adhesive capsulitis, also known as "frozen shoulder," is a common shoulder condition characterized by pain and decreased range of motion, especially in external rotation. Adhesive capsulitis is predominantly an idiopathic condition and has an increased prevalence in patients with diabetes mellitus and hypothyroidism. Although imaging is not necessary to make the diagnosis, a finding of coracohumeral ligament thickening on noncontrast magnetic resonance imaging yields high specificity for adhesive capsulitis. Traditionally, it was thought that adhesive capsulitis progressed through a painful phase to a recovery phase, lasting one to two years with full resolution of symptoms without treatment. Recent evidence of persistent functional limitations if left untreated has challenged this theory. The most effective treatment for adhesive capsulitis is uncertain. Nonsurgical treatments include nonsteroidal anti-inflammatory drugs, short-term oral corticosteroids, intra-articular corticosteroid injections, physiotherapy, acupuncture, and hydrodilatation. Physiotherapy and corticosteroid injections combined may provide greater improvement than physiotherapy alone. Surgical treatment options for patients who have minimal improvement after six to 12 weeks of nonsurgical treatment include manipulation under anesthesia and arthroscopic capsule release.