Siddha Medicine emphasises the theory of Interdependent phenomenon of the Universe and the Human Body and applies this law of nature in diagnosis and treatment of disease.
“The Body is in the Cosmos,
The Cosmos is in the body,
Whatever is present in the Cosmos,
Is present in the Human body”
The concept of Disease, according to the Siddha system, is explained through the Theory of Three Humours (Tri-dosha Theory). Siddha system of medicine classifies three humours namely Vali (Vatham), Azhal (Pitham), Aiyam (Kapham) and called this as Mukkuttram, which is the cause for health and disease. During every moment of life of human being, the three humors are in action through the 5 elements of nature. The three humors must have a harmonious relationship to keep the body and mind in healthy state. When they are disturbed, they bring about diseases peculiar to their influence.
The external air corresponds to the internal wind; the external Heat corresponds to the internal fire; and the external water corresponds to the internal fluids. Man is thus linked with the external world; and any change in the elementary condition of the external world has its corresponding change in the human beings. The interchange of these influences forms the basis of Tridosha theory of Siddha system of medicine.
Each humor is made up of two elements and possesses the qualities of both. For example Wind is influenced by air and space while Heat contains fire and water and Phlegm is made up of water and earth. No disease can be local or not connected to the other parts of the human body. Each humour namely Air, Fire and Phlegm must be in the proportions of 4: 2: 1 respectively. Any change in these ratios indicates the disease or death. Maintenance of their normal ratio gives vitality to the human beings and preserves the health and longevity of life.