The four humors of Medical astrology

The four humors and medical astrology.

To discover the nature of the humor offending, or quality of the disease, which that we may does, observe first what sign is in the sixth house, and what sign Ascends in the first house, in what sign the Lords of those houses are in; which being well understood, will acquaint us with the nature of the disease.

there are 4 humours, viz. Choler; Blood; Flegm, and Melancholly, so are they represented and governed by the 12 signs

Medieval Medicine: The Four Humors. ... The four humors were thought to be sanguine (blood), choleric (yellow bile), melancholic (black bile), and phlegmatic (phlegm) and their composition within the body was considered to determine a patient's personality and health concerns.

Agents of Metabolism

     The Four Humors are the metabolic agents of the Four Elements in the human body.  The right balance and purity of them is essential to maintaining health.  The Four Humors and the elements they serve are as follows:
     BLOOD - AIR
     PHLEGM - WATER
     YELLOW BILE - FIRE
     BLACK BILE - EARTH 
     All four of these humors, or vital fluids, are present in the bloodstream in varying quantities:
     Blood, or the Sanguine humor, is the red, hemoglobin-rich portion.
     Phlegm, or the Phlegmatic humor, is present as the clear plasma portion.
     Yellow Bile, or the Choleric humor, is present as a slight residue or bilirubin, imparting a slight yellowish tint.
     Black Bile, or the Melancholic humor, is present as a brownish grey sediment with platelets and clotting factors.