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 usually 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.

Complementary medicine is different from alternative medicine. Whereas complementary medicine is used together with conventional medicine, alternative medicine is used in place of conventional medicine. An example of an alternative therapy is using a special diet to treat cancer instead of undergoing surgery, radiation, or chemotherapy that has been recommended by a physician.

According to the National Center for Complementary and Alternative Medicine of the National Institutes of Health (NIH), complementary and alternative medicine (CAM) can include the following:

• acupuncture,
• Alexander technique,
• aromatherapy,
• Ayurveda (Ayurvedic medicine),
• biofeedback,
• chiropractic medicine,
• diet therapy,
• herbalism,
• holistic nursing,
• homeopathy,
• hypnosis,
• massage therapy,
• meditation,
• naturopathy,
• nutritional therapy,
• osteopathic manipulative therapy (OMT),
• Qi gong (internal and external Qiging),
• reflexology,
• Reiki,
• spiritual healing,
• Tai Chi,
• traditional Chinese Medicine (TCM), and
• yoga.