This unit group includes specialist physicians in clinical medicine, in laboratory medicine and in surgery. Specialists in clinical medicine diagnose and treat diseases and physiological or psychiatric disorders and act as consultants to other physicians. Specialists in laboratory medicine study the nature, cause and development of diseases in humans. Specialists in surgery perform and supervise surgical procedures. Specialists in clinical medicine usually work in private practice or in a hospital while those in laboratory medicine and in surgery usually work in hospitals. Residents in training to become specialist physicians are included in this unit group.