Many Americans use complementary and alternative medicine, commonly referred to as CAM. Complementary medicine is used together with conventional medicine, while alternative medicine is used in place of conventional medicine. The 2007 National Health Interview Survey (NHIS), which included a comprehensive survey of CAM use by Americans, showed approximately 38% of US adults currently utilize CAM treatments. Defining CAM is difficult, because the field is very broad and constantly changing, but it is best described as “a group of diverse medical and health care systems, practices, and products that are not generally considered part of conventional medicine, as practiced by holders of M.D. or D.O. (Doctor of Osteopathic Medicine) degrees, and by their allied health professionals such as physical therapists, psychologists, and registered nurses.” Conventional medicine (also called Western or allopathic medicine) is medicine as practiced by licensed M.D.s and D.O.s. The boundaries between CAM and conventional medicine are not absolute, and specific CAM practices may, over time, become widely accepted.
CAM practices are often grouped into broad categories, such as natural products, mind-body medicine, and manipulative and body-based practices.