According to the fundamental principles of Humoural Pathology, no disease can be local and absolutely unconnected with the other parts of the organism. If the physician tries to cure a disease, he should necessarily concentrate his attention upon the why and wherefore of the vitiated humours resulting in that disease. The principal rules to be followed in cases of irregularity of the three humours is either to augment the loss or deficiency, to pacify the aggravation or to reduce the increment of Doshas, Vata, Pitta and Khapa are in the proportions of 1 : 1 / 2: 1 / 4 : 4 : 2 : 1 respectively. The normal degree or force of pulse also is to be in the same order. Any change in these proportions is sure to bring about disease or death; but the maintenance of their normal proportion gives vitality to the organisms and assures the preservation of health and longevity of life.
It has already been stated that these three humours form these three fundamental principles in the composition and constitution of Man; and so the physiological doctrine on which they are based is also exactly the same as that of Pathology.
Let us now examine part played by each of these humours in the system:-
Vayu (wind) forms the vital force of the human body and is present everywhere in the system. It is believed to be self-begotten in its origin and identical with Divine Energy i.e., God. It is unconditioned, absolute and all prevading in its nature; and forms the lifeforce of all animated beings. Although it is invisible, its presence is manifest everywhere. It always takes a transverse course and is known by its two attributes namely, sound and touch. It is the root cause of all disease and the king of all sorts of aliments. It is very prompt in its action and it pass through the whole system in a rapid current.
Pitta (Heat) is the human organism is nothing but heat as it possesses all the characteristics of the external fire, such as burning, boiling, heating, etc. It produces the internal heat necessary to maintain the integrity of the human body; and any increase or decrease in this, produces a simultaneous action in the organism. The chief function of bile lies in metamorphosing the chyle to a proto-plasmic substance like the sperm in men and ovum in women. It corresponds to metabolism or cell sub-division. Heat may be said to include both bile and metabolism of tissues as well as the bodily heat which is product of the latter. It is also viewed by some that Pitta is the name for the heat incarcerated in the liquid bile - the principal agent in digestion and in purging out of the waste matter in the form of urine and feces. The origin of bile is in the liver. In the heat, bile brings about the realisation of one’s desire; in the eyes the catching of the images of external objects; and in the skin, the absorption of the lubricating substances that are applied to the skin. It is blue in its normal colour and yellowish in its deranged condition; and it turns into an acid when deranged or vitiated. Pitta (heat) in its normal state remains in the lymph, chyle, blood and saliva but chiefly in the stomach. It gives sight to the eyes, beauty to the skin and cheerfulness to the mind. Its derangement causes sleeplessness, indigestion, red boils, jaundice, chlorosis, ulcers, catarrh, dropsy, haemorrhage, acidity, eructation, delirium, perspiration, thirst, bitter taste in the mouth, burning sensation in the body especially palms and soles, etc.
Khapa (phlegm) supplies the body with moisture even as Pitta furnishes it with heat and imparts stability and weight to the body. It adds to the strength of the body, increases the firmness of the limbs and keeps them united, preventing their disunion. It helps digestion by moistening and disintegrating food with its humid essence. It imparts to the tongue the power of taste and helps the sense-organs like the eyes, ears and the nose in the performance of their respective functions. Its derangement causes excess of thirst, dull appetite, throwing out of phlegm in cough, goitre, Urticaria etc. Meals taken before digestion, day-sleep, taking sweats, molasses etc., generally aggravate Phlegm.
The existence of these three humours in the human system in due proportion is well indicated by plus without which no correct diagnosis of disease if possible to get oneself well acquainted with the inner working of a disease, inner vision, intuition and the spiritual sense are absolutely necessary as it cannot otherwise be easily judged from a material point of view. It is only spiritual knowledge endowed with inner vision that will enable a physician to diagnose a disease at sight and suggest forthwith remedies therefore. A Physician who is incapable of entering into spirit of his patient by the light of knowledge, intellectual faculties and imaginative penetration would be of no use for the diagnosing or treating of human diseases.