The term alternative medicine, as used in the modern Western world, encompasses any healing practice "that does not fall within the realm of conventional medicine". Commonly cited examples include naturopathy, chiropractic, herbalism, traditional Chinese medicine, Unani, Ayurveda, meditation, yoga, biofeedback, hypnosis, homeopathy, acupuncture, and diet-based therapies, in addition to a range of other practices. It is frequently grouped with complementary medicine, which generally refers to the same interventions when used in conjunction with mainstream techniques, under the umbrella term complementary and alternative medicine, or CAM. Some significant researchers in alternative medicine oppose this grouping, preferring to emphasize differences of approach, but nevertheless use the term CAM, which has become standard.Cassileth BR, Deng G. (2004) Complementary and Alternative Therapies for Cancer The Oncologist PMID 14755017Elsevier Science - Interview with Edzard Ernst, editor of The Desktop Guide to Complementary and Alternative Medicine

Alternative medicine practices are as diverse in their foundations as in their methodologies. Practices may incorporate or base themselves on traditional medicine, folk knowledge, spiritual beliefs, or newly conceived approaches to healing. Jurisdictions where alternative medical practices are sufficiently widespread may license and regulate them. The claims made by alternative medicine practitioners are generally not accepted by the medical community because evidence-based assessment of safety and efficacy is either not available or has not been performed for many of these practices. If scientific investigation establishes the safety and effectiveness of an alternative medical practice, it may be adopted by conventional practitioners. "It is time for the scientific community to stop giving alternative medicine a free ride. There cannot be two kinds of medicine -- conventional and alternative. There is only medicine that has been adequately tested and medicine that has not, medicine that works and medicine that may or may not work. Once a treatment has been tested rigorously, it no longer matters whether it was considered alternative at the outset. If it is found to be reasonably safe and effective, it will be accepted. But assertions, speculation, and testimonials do not substitute for evidence. Alternative treatments should be subjected to scientific testing no less rigorous than that required for conventional treatments." Because alternative techniques tend to lack evidence, some have advocated defining it as non-evidence based medicine, or not medicine at all. Some researchers state that the evidence-based approach to defining CAM is problematic because some CAM is tested, and research suggests that many mainstream medical techniques lack solid evidence.