Despite considerable efforts to understand the anatomy and physiology of the “acupuncture points,” the definition and characterization of these points remains controversial. Even more elusive is the scientific basis of some of the key traditional Eastern medical concepts such as the circulation of Qi, the meridian system, and other related theories, which are difficult to reconcile with contemporary biomedical information but continue to play an important role in the evaluation of patients and the formulation of treatment in acupuncture.