Chinese medicine has been used for thousands of years. The tradition may have its roots in the shamanic era of the Shang Dynasty (1600 to 1046 B.C.). At the time, illness was generally attributed to curses or demons sent by a disgruntled ancestor. Shamans would break turtle shells and scapular bones with a heated rod, then divine the will of the ancestors from the shape of the crack.
Chinese medicine shifted from the shamanistic worldview to a more disciplined and systematic medical model during the Zhou Dynasty (1050 – 221 B.C.). The practice was further formalized after the Warring States period (475-221 BC) when scholars began compiling records into a medical canon that would inform TCM to this day.