Traditional Chinese Medicine
Before 2,500 BC ancient the belief was that disease was caused by the invasion of demons into the body. The first classic Chinese medical text is the Nei Jing Su Wen (300BC - 800AD) or "The Yellow Emperor's Classic of Internal Medicine" which set out clearly the ideas and belief structures behind acupuncture, and other associated Chinese Medical Practices. To gain an understanding in TCM it is a good place to start, and the translations into English are easy to read and beautifully worded.
A Western doctor observes the facts before him and uses current physiological theories to explain them. Chinese medicine is based on a much wider world view, which is described in the Nei Ching Su Wen and these ideas are woven into a complete and intact system based on a philosophy different from that of modern Western medicine. The concepts of Yin and Yang, for example, is the foundation of much of traditional Chinese scientific & medical thought.