D.O.s (like M.D.s) are licensed in all 50 states and the District of Columbia to diagnose, treat, prescribe drugs, and perform surgery. D.O.s, like M.D.s, can specialize in any branch of medicine. However, D.O.s must complete three years of general practice before becoming board certified. Although they can perform many procedures themselves, they should never attempt to perform major operations without proper training and assistance from more experienced physicians. In fact, several studies have shown that patients who have had unsupervised surgical procedures face increased risks of mortality and serious long-term health problems. Major surgeries require extensive training and experience. You should not try to perform major surgeries on yourself if you do not have the right education or equipment. Even with the best intentions, these procedures can lead to serious complications or death. Surgery is a special form of treatment that involves the removal of tissue or organs to cure disease or improve function. Surgical procedures are usually needed for cancer diagnosis and treatment. Surgery can also be used to remove tumors, repair injuries, correct deformities, and treat numerous other conditions. The word "surgeon" comes from the Latin term for "master," which makes sense because surgeons are responsible for repairing and improving their patients' conditions.