One of the important diagnostic techniques of the ancient science of Ayurveda is 'Nadi vijñan' or pulse diagnosis.

The first Ayurvedic classic to describe pulse examination is Saarangadhara Samhita (13th century AD.). Later works such as Bhavaprakasa (15th century AD.), Yogaratnakara (16th century AD.), Basavarajeeyam (17th century AD.) etc. deal extensively with the subject.

Pulse diagnosis is the ancient art and science of detecting the existing status of a person’s body, mind, soul and spirit. Nadi or pulse is that vital flow of energy or life that courses through as a subtle channel all over the body, and enables the vaidya to feel the way the blood spurts from the heart. To a skilled practitioner, taking your pulse is more than counting the beats. The functioning and health of the entire mind body constitution can be determined from the pulse, including the balance of the doshas, the health of the various organs, advance warning signs of potential problems that may crop up later etc. By detecting early symptoms of imbalance and disease reaction in the body, one can take preventive steps to correct the problem before it manifests into a major one.

Classical pulse exmination
Radial pulse is felt with the first three fingers, the index, middle and ring fingers. Pulse from both wrists are taken. To get an accurate pulse, the patient should be as close to his norm as possible. Taking pulse after strong exertion, after exposure to a severe environment etc. will give wrong indications.

The position of the index finger denotes the Vata dosha. When vata is strong in the constitution, the index finger will feel the pulse strongly. The pulse will be irregular and thin moving in waves like the motion of a serpent. This type of pulse is called a snake pulse.

The middle finger denotes the pulse corresponding to the Pitta dosha. When the person has a predominant pitta constitution, the pulse under the middle finger will be stronger. Ayurveda describes this pulse as "active, excited, and move like jumping of a frog." This pulse is called frog pulse.

When the throbbing of the pulse under the ring finger is most noticeable, it is a sign of Kapha constitution. The pulse feels strong and its movement resembles the floating of a swan. Hence, this pulse is called swan pulse.

Pulse Diagnosis
In Western diagnostics it is only the rate of the pulse that is taken. The rate is dependant on the dominance of the Doshas in Ayurveda. Vata is 80-90 beats per minute. Pitta is 70-80 bpm. Kapha is 60-70 bpm. The rhythm of the pulse can be irregular or regular. An irregular pulse has no distinguishable pattern. Its intensity and rhythm fluctuates wildly. Vata is irregular. A regular pulse in consistent, it pumps in the same rhythm and amplitude. Its crest and wave are even. Pitta is regularly irregular, meaning that if it skips a beat it always skips that beat, and thus the pattern repeats itself. The amplitude of the pulse is the force or strength with which the beat moves into the fingers. Pitta's intensity is high, Kapha's consistency is moderate, and Vata's variability is low. Overall the characteristics of each dosha are: Vata is feeble and light as it slithers into the fingers. Pitta bounds into the fingers strongly and clearly. Kapha slides into the fingers slow and cloudlike. These are elaborated on in the table below.

	VATA	PITTA	KAPHA
Characteristics	Fast, feeble, cold, light, thin, disappears on pressure	Prominent, strong, high amplitude, hot, forceful, lifts palpating finger	deep, slow, broad, wavy, thick, cool or warm, regular
Location	Index	Middle	Ring
Gati	Sarpa (Cobra)	Manduka (Frog)	Hamsa (Swimming Swan)
Vega (Rate)	80-95	70-80	50-60
Tala (Rhythm)	Irregular	Regular	Regular
Bala (Force)	Low +	High +++	Moderate ++
Akruti (Tension and Volume)	Low	High	Moderate
Tapamana (Temperature)	Cold	Hot	Warm to cool
Kathinya ( vessel wall)	Rough, hard	Elastic, flexible	Soft thickening

The qualities listed above are the "home" qualities of the pulse for that dosha. In other words, one would expect to feel the pulse jumping like a frog with the middle finger because that is the normal quality of the Pitta pulse. Vata would normally feel like a Cobra (snake) and Kapha like a smooth swan.

Under different conditions, these qualities can leave their home location and appear at the home of one of the other doshas. For example, the frog quality can move from Pitta (the middle finger) to Vata (the index finger) at times.

When the qualities of the pulse are not at home, it can indicate an imbalance in one's health.

Proficiency in pulse diagnosis is gained by long practice, alertness and guidance from the preceptor. Though learning to detect disease from the pulse is a skill belonging to the physician, you can also become familiar with your own pulse and glean fascinating insights into doshas. Once you have worked with your doshas you can easily attribute them to pre-mentioned qualities, signs, symptoms etc. of corresponding doshas in the classical texts. From this data-base, you can gain true intimacy with your own doshas.