There are many terms used to describe approaches to health care that are outside the realm of conventional medicine as practiced in the United States. Complementary and Alternative medicine (CAM) is a group of diverse 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 complementary medicine and conventional medicine.

While some scientific evidence exists regarding some complementary medicine 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.

The list of what is considered to be CAM changes continually, as those therapies that are proven to be safe and effective become adopted into conventional health care and as new approaches to health care emerge.

Complementary medicine is used together with conventional medicine.

Alternative medicine is used in place of conventional medicine.

Integrative medicine combines treatments from conventional medicine and CAM for which there is some high-quality evidence of safety and effectiveness. It is also called integrated medicine.

Whole Medical Systems
Whole medical systems are built upon complete systems of theory and practice. Often, these systems have evolved apart from and earlier than the conventional medical approach used in the United States. Examples of whole medical systems that have developed in Western cultures include homeopathic medicine and naturopathic medicine. Examples of systems that have developed in non-Western cultures include traditional Chinese medicine and Ayurveda.

Mind-Body Medicine
Mind-body medicine uses a variety of techniques designed to enhance the mind’s capacity to affect bodily function and symptoms. Some techniques that were considered CAM in the past have become mainstream (for example, patient support groups and cognitive-behavioral therapy). Other mind-body techniques are still considered CAM, including meditation, prayer, mental healing, and therapies that use creative outlets such as art, music, or dance.

Biologically Based Practices
Biologically based practices in CAM use substances found in nature, such as herbs, foods, and vitamins. Some examples includedietary supplements, herbal products, and the use of other so-called natural but as yet scientifically unproven therapies (for example, using shark cartilage to treat cancer).

Manipulative and Body-Based Practices
Manipulative and body-based practices in CAM are based on manipulation and/or movement of one or more parts of the body. Some examples include chiropractic or osteopathic manipulation, and massage.

Energy Medicine
Energy therapies involve the use of energy fields. They are of two types:

  • Biofield therapies are intended to affect energy fields that purportedly surround and penetrate the human body. The existence of such fields has not yet been scientifically proven. Some forms of energy therapy manipulate biofields by applying pressure and/or manipulating the body by placing the hands in, or through, these fields. Examples include qi gong,Reiki, and Therapeutic Touch.
  • Bioelectromagnetic-based therapies involve the unconventional use of electromagnetic fields, such as pulsed fields, magnetic fields, or alternating-current or direct-current fields.

from NIH