What is Complementary and Alternative Medicine (CAM)?

This is the definition from the National Center for Complementary and Alternative Medicine (NCCAM) in the United States:

CAM is a group of diverse medical and health care systems, practices, and products that are not presently considered to be part of conventional medicine. Conventional medicine is medicine as practiced by holders of M.D. (medical doctor) or D.O. (doctor of osteopathy) degrees and by their allied health professionals, such as physical therapists, psychologists, and registered nurses. Some health care providers practice both CAM and conventional medicine. While some scientific evidence exists regarding some CAM therapies, for most there are key questions that are yet to be answered through well-designed scientific studies—questions such as whether these therapies are safe and whether they work for the diseases or medical conditions for which they are used.

Generally Complementary medicine is used together with conventional medicine. An example of a complementary therapy is using aromatherapy therapy (in which the scent of essential oils from flowers, herbs, and trees is inhaled to promote health and well-being) to help lessen a patient’s discomfort following surgery.

Alternative medicine is used in place of conventional medicine. An example of an alternative therapy is using a mind body intervention to treat hypertension instead of starting a patient on pharmacotherapy.