Many Americans—more than 30 percent of adults and about 12 percent of children—use health care approaches developed outside of mainstream Western, or conventional, medicine. When describing these approaches, people often use “alternative” and

'complementary” interchangeably, but the two terms refer to different concepts:

• If a non-mainstream practice is used together with conventional medicine, it’s considered “complementary.”

• If a non-mainstream practice is used in place of conventional medicine, it’s considered “alternative.”

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