M.D.s are physicians who have earned a degree of Doctor of Medicine (M.D.) by completing an approved course of study at an approved allopathic medical school.
D.O.s are physicians who have earned a degree of Doctor of Osteopathy (D.O.) by satisfactorily completing a course of education in an approved college of osteopathic medicine. Osteopathic physicians and Medical (M.D.) physicians follow nearly identical courses of training and modes of practice, except that osteopathic medicine places an additional emphasis on treatment that involves manipulation of body structures.
A chiropractor is awarded the degree of Doctor of Chiropractic, or D.C., after completing at least two years of premedical studies followed by four years of training in an approved chiropractic school. In most cases, treatment provided by chiropractors involves the mechanical manipulation of the spinal column. Some practitioners employ radiology for diagnosis and use physiotherapy and diet in addition to spinal manipulation. In most cases, chiropractors are not licensed to prescribe controlled medications and, in general, Chiropractic does not use drugs or surgery.