Nyepas, the three humors
Buddha Baishajaya Guru said in the beginning of the first tantra:
“Health sustainment or decline is defined by the Normal or abnormal state of the Humors, body constituents and waste products”.
As described in the mind chapter, the mind is the background, the pillar of life, the hidden power, the essence, and the covering of the body which provides the base for the physical body to exist. The humors then build the body constituents and develop the system of the body and its functions, and are the basis of the theory and practice of Tibetan Medicine. The theory describes the three principles of the humors and their threefold causes (mental predisposition, elemental energy and physical cause) and their functions.
The mental predispositions cause of the three humors First of all, even before the physical actions, the mind plays its role. Marigpa (ignorance) is the source of everything including of the mind, itself. Ignorance produces the three mental predispositions and the delusions of the mind of the bardo consciousness, which unites with the parent’s two physical energies[1]. This is the start of life, as we are told in the first and second tantras. Consequently to the unification of the mind and matter, the mind becomes the cause of the manifestation of the three humors: attachment is the precondition for rLung[2]/Wind humor, hatred for mkhrispa/Bile, and closed-mindedness for Badken/Phlegm humor. These three energies arise respectively from the mental predispositions of the mind and become the psychic cause of the three humors.
The elemental energy cause of the three humors Secondly, the energy cause for the three humors arises from the five elements energies: the wind element produces the Wind humor, the fire element manifests Bile, and the earth and water elements produce the Phlegm humor. The ether or space element is pervasive to all humors like the globe of Earth hanging in space and supported by all the five elements.
The physical cause of the three humors Thirdly, the physical or material causes of the three humors are: the subtle wind element which carries the bardo consciousness during its journey, and becomes the cause of the Wind humor and the nervous system; the sperm, which is the cause of the Phlegm humor and of the lymphatic and endocrine systems; the menstrual blood (ovum), which is the cause of the Bile humor, the blood and blood circulation and of the metabolic systems.
The three humors, through their triple-fold dimension (psychic, energetic and physical) develop the body, and govern the body/mind and its functions. They rule physiology, anatomy and morphology, regulate the functioning of the body, its organs, the brain, nerves, bones, blood circulation, lymphatic systems, digestion etc. Balanced humors give positive health and harmony to the body/mind, and provide a good base for the development of the body/mind, the immune system and protection. On the contrary, the loss of balance among the humors causes energy disharmony and physical and mental disequilibrium which may appear at any time and become the cause of diseases.
[1] About the subtle wind with other elements, see more in the embryology chapter [2] rlung should be pronounced like ‘lung‘, mkhrispa like ‘Tripa‘ and Badken like ‘Beken‘
Source
http://www.tibetanmedicine-edu.org/index.php/n-articles/the-3-humors-part-1