Etiology or the causation of disease according to Ayurveda

Health is when a person's Dhatu-equipoise is normal, and ill - health, when it is abnormal. Vata, Pittha and Kapha, which are spoken of as Dhatus when in their normal equipoise are referred to as Doshas (Faults) when their equipoise becomes abnormal; because in this condition of abnormality they vitiate or cause faults in the secondary Dhatus, like Rasa, Rakta, etc

1) Asathmyendriyartha Samyoga

Incompatible correlation of Indriyas (Senses) with their Artha (Objects) - Ayurvedists explain this is follows:- Bhautika Dravyas (Panchabhutic Substances or physical objects) cannot make for health or ill-health without coming into contact with our bodies. Such contacts can occur in only five ways - that is through the five senses (Indriyas) which are our normal channels for contacting all objects already known as well as those which becomes known here after. These five ways of contact of Indriyas with external objects can show abnormalities of three kinds viz. Atiyoga (Excessive Degree of correlation), Heenayoga (Defective degree of correlation) and Mithya Yoga (Correlation of Faulty quality). The underlying idea of this classification may be stated thus all external objects that can invade our bodies to cause diseases - whether they be physical agents, chemical substances, microbes, parasites or any other - can enter our bodies in only five ways - through the channels of our five senses, and each of those five ways or modes of entry may exhibit three variations from the standpoint of their capacity to cause diseases viz. variations from nor man by way of excess (Atiyoga), defect (Heenayoga) or qualitative change (Mithya-Yoga).

Under this classification, diseases caused, say, by blinding light falling on the retying and injuring the eye deafening sounds falling on the ears and injuring the ears, foods and drinks taken injurious excess etc., would be described as diseases caused by Atiyoga (excessive contact or correlation of light, sound, foods and drinks, etc., with the senses of sight, sound, taste, small and touch) senses of sight, sound, taste, smell and touch) Similarly, diseases caused by abnormal quantitative defects instead of by abnormal increases as in the examples given above would be described as diseases caused by Heenayoga (defective contact or correlation) of light, sound, foods and drinks etc., with senses of sight, sound, taste etc Diseases caused by injurious rays, foods and drinks, etc., would be described as caused by Mithya Yoga (Quantitatively abnormal correlations or contacts) of sight, foods and drink, etc., with sense of light taste etc.,

2) Prajnaparadha

Faults of understanding, also known as karma. The phenomena coming under this category are classified under three heads viz.: Shareeram (relating to body), Manasam (relating to mind), and Vachikam (relating to speech) and these become cause of disease when faulty understanding causes excessive, defective or perverted correlations of such phenomena (Atiyoga, Heenayoga) and mithyoga) resolting in abnormality of Dhata-balance.

3) Parinama

Also known as Kala. This is quite a technical word which has reference to seasonal and other phenomena governed by the time factor (kala). If, by excess, defect or perversion (Atiyoga, Heenayoga, or Mithya Yoga) they become abnormal, then, they may cause diseases, by way of causing Dosha Vaishamya (Abnormality of normal dosh-equilibrium). Thus, ill-health may be caused by such agencies of abnormally severe or mild seasons, the prevalence of winter conditions during summer or to rain during the non-rain season and so on. This category also includes karmic causes which are stated to cause manifestation of disease at the time of Karma Vipaka - the time when the Karmic seeds become mature or ripened by Parinama.

4) Guna Vaishamya

(Abnormality in equilibrium of the gunas - a term which has been explained.) Of the three Gunas, Satwas, Raja and Tamas, it is held that only Rajas (stimulator) and Tamas (inhibitor) can become Doshas (or faults) while satwa (Balance of Harmony) is always a Guna and never a Dosha. This category has reference to mental doshas (Manasa Dosha). Capidity, (ruelty, anger, rage, jealousy, indolence, self indulgence etc., are mental Doshas or Faults. The time has gone by when some well - meaning students of Western Medicine used to say that Ayurveda unscientifically mixes up Ethies and Medicine in laying down, as it does, that unethical conduct (for example, getting into a fit of anger, rage or jealousy) was one of the causative factors of disease.