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 Ayurveda, Yoga, Naturopathy, biofeedback, , Homeopathy, Yunani, Siddha 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.
A 1998 systematic review of studies assessing its prevalence in 13 countries concluded that about 31% of cancer patients use some form of complementary and alternative medicine. Alternative medicine varies from country to country; Dr. Edzard Ernst believes that in Austria and Germany CAM is mainly in the hands of physicians, although some estimates suggest that half of CAM is administered by physicians in the US. In Germany, herbs are tightly regulated, with half prescribed by doctors and covered by health insurance based on their Commission E legislation.