A general surgeon is a type of medical surgeon who specializes in surgical procedures to diagnose or treat a medical condition. They have specialized knowledge of the entire surgical process, from the initial evaluation through preparation, procedure, and post-operative management. General surgeons are trained to diagnose and manage a wide range of diseases and disorders that may require surgical treatment, and their area of expertise is essentially the entire body. They are responsible for the preoperative, operative, and postoperative management of patients with a wide range of conditions. General surgeons are trained in all nine basic areas of surgery, which include the digestive tract, the abdomen and its contents, the skin and soft tissue, including the breasts, the head and neck, the blood vessels and heart, the endocrine system (hormones and glands), and surgical treatment of cancer. Some general surgeons also perform vascular and trauma surgery, which always involves critical care. To become a general surgeon, a person must complete four years of medical school and then a five-year residency in surgery. Many general surgeons go on to do two- to three-year fellowships in surgical subspecialties such as complex general surgical oncology.