An idea from Daoism/traditional Chinese medicine relates to the Siming. Also known as the sanshi ( "Three Corpses") or sanchong ( "Three Worms"), the Three Deathbringers are part of a Daoist physiological belief that demonic creatures live inside the human body, and they seek to hasten the death of their hosts. These three supernatural parasites allegedly enter the person at birth, and reside in the three dantian "energy centers" (head, chest, and abdomen). Succeeding the demise of their human host, they become free of the body as malevolent "ghosts". However, this process is regulated by Siming, who may or may not permit this process: in this regard, Siming is said to rely on the reports which the Three Deathbringers (and perhaps Kitchen God) provide on specifically regulated dates. Based on these reports, and perhaps other information, Siming alters the fine yin-yang balance of each individual, thus regulating each one's health or sickness, and ultimately each's lifespan. Nevertheless, humans are believed to have various recourses available to alter the judgement of Siming regarding their fates, such as interfering with the reporting process, praying to Siming or his superiors, or following treatment from a doctor to improve the yin-yang balance, and thus extend the lifespan.
