Typically, alternative medicine differs from traditional medicine in that alternative medicine is older and what we might call unconventional or non-Western medicine. Alternative medicine does not follow the traditional science and research that current medicines undergo. Alternative medicine could also be termed complementary or traditional medicine or the therapies that can be integrated into current medicine. The staff of the National Library of Medicine of the United States classified alternative medicine under the category of complementary therapies in their Medical Subjects Heading Section. This was done in the year 2002. The definition provided was that alternative medicine therapeutic practices were not considered as an integral part of the traditional allopathic medicine. Therapies like acupuncture, dieting, physical therapy like exercises or yoga, etc. are termed as alternative medicine. These therapies are called complementary when they are used along with conventional treatments. If they are done in place of conventional treatments, they are known as alternative treatments.