Doctor and physician are the same.

They hold a medical degree and a license to practice medicine. Sometimes after the term physician, you may add on other terms to clarify or to be more specific of course, such as: médico que efectua (o exame, estudo)/ médico solicitante/médico que encaminhou/médico assistente, etc.........
Hope this helps!!!!

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Note added at 34 mins (2007-09-03 02:30:18 GMT)
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To further clarify my answer,
There are two types of physicians: M.D.—Doctor of Medicine—and D.O.—Doctor of Osteopathic Medicine. M.D.s also are known as allopathic physicians. While both M.D.s and D.O.s may use all accepted methods of treatment, including drugs and surgery, D.O.s place special emphasis on the body’s musculoskeletal system, preventive medicine, and holistic patient care. D.O.s are more likely than M.D.s to be primary care specialists although they can be found in all specialties. About half of D.O.s practice general or family medicine, general internal medicine, or general pediatrics.

Physicians work in one or more of several specialties, including, but not limited to, anesthesiology, family and general medicine, general internal medicine, general pediatrics, obstetrics and gynecology, psychiatry, and surgery.