Clusters of medically unexplained physical symptoms have been referred to in the literature by many different labels, including somatization, symptom-based conditions, and functional somatic syndromes, among many others. The traditional medical perspective has been to classify and study these symptoms and functional syndromes separately. In psychiatry, current taxonomies (Diagnostic and Statistical Manual of Mental Disorder, 4th edition, and The International Statistical Classification of Diseases and Related Health Problems, 10th revision) classify these syndromes together under the rubric of somatoform disorders. In this article we approach medically unexplained physical symptoms from a psychiatric perspective and discuss the common features that unite multiple unexplained symptoms or functional somatic syndromes as a class. Included in this article is a discussion of nosological issues, clinical assessment, how these syndromes are viewed within the various medical specialties, and clinical management and treatment.