The signs and symptoms as appearing on the tongue are considered. Factors like size of the tongue, thickness, coating and patches on the tongue surface, fissures (longitudinal and transverse) on the tongue, sense of taste, secretion of saliva are taken in to consideration. Examining tongue can show directly sign and symptoms of condition like Oral Aphthous Ulcer, Oral Hairy Leucoplakia, Oral Candidiasis, etc.

Color of the Naa or tongue plays a pivotal role in the diagnosis. It is black in vatham, yellow or red in pitham and pale in kapham.

The change in the normal sound of the voice, the speech tonality, the pitch is observed by the Siddha practitioner in this diagnostic method. Factors like Uratha oli (Valithal), thazhntha oli (Melithal), physiological and mental status are noted during the conversation and reported. As a general rule, the voice is normal in vatham, high-pitched in pitham and low-pitched in kapham.

The color of the skin is mainly considered here. The change of color of other organs is also considered alongside. As a general rule, it is dark in vatham, yellow or red in pitham and pale in kapham.

The color of the eye, warmth in the eye, a burning sensation, irritation in the eyes, visual perception, etc are the factors considered. Generally the observation is a muddy conjunctiva in case of vatham, yellow or red in pitham and pale in kapham.

When the patient is touched, the temperature, sensory impairment, texture of the skin, pain, hardness, and dullness are observed and noted as part of diagnosis. Such physical anomalies like masses, nodes, edematous or common swellings are observed during touch.

When touched, the general rule is if it is dry it is vatham, warm if pitham and chill if kapham.

The stool of a patient is examined for quantity, the hardness factor (very hard to loose-motion), its color and smell. As a general rule, black stools indicate vatham, yellow stools indicate pitham and pale stools indicate kapham.

The Early morning urine discharged by the patient is taken for analysis and is examined. The factors like color, quantity, specific gravity, odor, frothing quality, and deposits if any are observed in a urine sample. As a general rule, straw-colored urine indicates indigestion, reddish-yellow urine indicates excessive heat and saffron color indicates jaundice.

Another unique diagnostic method practiced exclusively by Siddha Medicine is the Neykuri Analysis. In this unique methodology, fresh sample of few drops of early morning urine is collected. On this sample, a drop of sesame oil is added to the surface. The oil spread on the urine sample and shows different pattern for different people. If the pattern displayed is of a snake, it indicates Vatham. If the pattern displayed is ring-shaped, it indicates Pitham. If the pattern is pearl-like in shape, it indicates Kapham.

When the index and middle finger are joined and softly pressed over the blood vessel that runs below the thumb, pulse beats can be felt. Anyone can feel the pulse of a body and can measure the heart rate or pulse rate. But only an experienced Siddha or an Allopathy practitioner can read the pulse for its rhythmic patterns and infer diseases.

As a general rule, experienced Siddha practitioners can read the degree of distortion or rhythmic changes of a vatham, pitham and kapham pulses.