Acupuncture, one of the main forms of therapy in Traditional Chinese Medicine (TCM), has been practiced for over 2,500 years. In acupuncture, certain points on the body associated with energy channels or meridians are stimulated by the insertion of fine needles. Unlike the hollow hypodermic needles used in mainstream medicine to give injections or draw blood, acupuncture needles are solid. Acupuncture is thought to restore health by removing energy imbalances and blockages in the body. Practitioners of TCM believe that there is a vital force or energy called qi (pronounced "chee") that flows through the body, and between the skin surface and the internal organs.