The Physician examines the tongue, complexion, speech, eyes, urine and stools. The interrogation plays only a very minimal role. The siddha methodology of diagnosis is based on the clinical examination of the physician. These diagnostic tools not only help for diagnosis but also to learn the prognosis for the restoration of health.

The siddha methodology of diagnosis is based on the following eight investigations.

1. Tongue (Na):

The tongue is an important indicator. If the tongue is blackish, it indicates a vatha disease, if red, a pitha disease, and if white, a kapha disease.

2. Skin (Mei):

The same inferences as in tongue color.

3. Eye (Vizhi):

Eye discoloration is a critical indication, the color indications as the tongue.

4. Speech (Mozhi):

Speech is another element in diagnosis. The tone, voice and clarity indicates the type of problem.

5. Pulse Examination (Naadi):

This is the most important diagnostic tool of siddha medicine. The pace and tempo of the pulse indicates the type of constitution and the irregularities present in the body. The pulse is examined in the Right hand of males and the left hand for females. The pulse is recorded at the Radial-artery. The unit of pulse diagnosis isĀ 1 for Vatham 1/2 for Pitham and 1/4 for Kapham. This unit is equivalent to the size of a grain (wheat).

6. Faecal Examination (Mala kuri):

If the faeces is black, it indicates a vatha disease, if red a pitha disease and if white a kapha disease.

7. Urine Examination (Neer kuri):

A sample of early morning first urine is collected. The color of the urine is indicative of various diseases. Straw color indicates indigestion reddish-yellow indicates excessive heat, a rose tinge, blood pressure, and so on.

8. Oil in urine examination (Nei kuri):

Urine is kept in a tray, in sunlight a drop of oil is placed gently on it with a rod if it spreads like a snake, it indicates vatha. If it appears as a ring it indicates pitha, if it floats like a pearl it is kapha.