Complementary and alternative medicine (CAM) therapies play a 

key role in the health care of many Americans. The National Center for 

Complementary and Alternative Medicine reports that in the United 

States, about four in 10 adults and about one in nine children use some 

form of CAM, such as deep breathing, dietary supplements, massage, 

meditation, or yoga. CAM, alone or in conjunction with mainstream 

medicine, is often used to treat an increasing variety of diseases and 

conditions, such as arthritis, anxiety, back pain, cancer, diabetes, heart 

disease, and sleep problems.