The Shanghan Zabing Lun or the Treatise on Cold Damage and Complex Diseases is considered the forefather of all formula books. The original work was lost to the tooth of time, but most of its contents are preserved in two extant works called the Treatise on Cold Damage shanghan lun and the Concise Essentials of the Golden Cabinet jingui yaolue. The first work primarily addresses externally triggered disorders while the latter work describes the pathology and treatment of complex diseases generated internally.