complementary medicine A group of diagnostic and therapeutic disciplines that are used together with conventional medicine. An example of a complementary therapy is using aromatherapy to help lessen a patient’s discomfort following surgery. Complementary medicine is traditionally not taught or used in Western medical schools or hospitals. Complementary medicine includes a large number of practices and systems of health care that, for a variety of cultural, social, economic, or scientific reasons, have not been adopted by mainstream Western medicine. See also alternative medicine; conventional medicine.