Despite differences in training and philosophy of treatment, both M.D.'s and D.O.'s use all accepted methods of treatment, including drugs and surgery. One of the basic treatments or therapies used by osteopathic physicians centers on manipulating this system with the hands. Physician may be general practitioners or they may specialize in a particular field of medicine. On the other hand, about 85 percent of the M.D.'s who provide patient care are specialists. The largest of the medical specialties for which there is graduate medical training are internal medicine, family medicine, general surgery, obstetrics and gynecology, psychiatry, pediatrics, radiology, anesthesiology, ophthalmology, pathology, and orthopedic surgery.
Some physicians combine the practice of medicine with research or teaching in medical schools.
Advances in medical technology in recent years have been many and dramatic. Liver and kidney transplants, laser surgery, and ultrasound and magnetic resonance imaging are but a few of these new technologies. The emphasis on technology has implications for the way physicians are trained and the way they practice medicine. High-technology medicine requires extensive skills and training. Its dominant role in American medical care underlies the system of specialty medicine, whereby most M.D.'s are specialists and a few are general practitioners.