In Ayurveda, pulse is considered as a subtle manifestation of universal consciousness runs through a person’s constitution. The Sanskrit literature contains a number of words that can be translated as Pulse. The most commonly used word is nadi, which means a river of life expressed through the pulse although there are other words like snayu, tantu hamsi etc are used often.
Ayurveda uses darshana ( inspection ), sparshana ( palpation ) and prashna ( interrogation ) as the clinical barometers and they apply to Nadi vijnanam as well. In this context, Sparshana is the tactile experience from most perceptible blood vessels, that can be radial pulse, temporal pulse, jugular pulse, carotid pulse, or femoral pulse, based on the clinicians understandings, diagnostic relevance and patient’s convenience. The basic principle of diagnosis starts by categorising the pulses based on doshic status. Vata pulse is superficial, cold, light, thin and feeble. It moves fast and may become irregular. It is best felt under index finger. Vata pulse is cold to touch because of insufficient insulating material in the form of subcutaneous fat which is why people with a vata constitution lose heat and hate cold.
Pitta pulse is full with a strong throb. It is hot and abrupt with high amplitude, good volume and considerable force. It is best felt under the middle finger, is hot to the touch because pitta people have strong body heat and high BMR( Basal metabolic rate). Kapha pulse is deep, slow, watery, wavy and cool to the touch. People with kapha constitution retain heat in the body because of the thick layer of fat under the skin. The temperature of the pulse will be sometimes cold or warmth based on the underlying pathology of the patient.
The position for reading these pulse is very important. The rule is to feel the pulse from the radial side and never from the ulnar side. When viewing the body in the anatomical position, the radial side next to the thumb is considered the outer side and the inner side next to the little finger is the ulnar side. On the radial side there is a bony protuberance called radial tubercle. There are two schools of thought about finger placement. The index finger can be placed above or below the radial tubercle. If the finger is placed above the radial tubercle, a gap is created between the distal and middle fingers, so some authorities say to avoid the radial tubercle. However, the index finger is never placed on radial tubercle because this position will give an incorrect reading.
Other than the dosic pulse, Disbalance of doshas and it’s underlying pathologies are best felt under seven category of pulses. Even though the gross manifestation of the three doshas are perceived under the index, middle and ring finger their subtle qualities are felt under each finger at the distal, middle and proximal curvatures.
While feeling the pulse, the most subtle dosha is vata. It is light, mobile and subtle. With very little pressure the flow can be blocked. Even if vata is partially blocked by the fingers, its subtlety will not create a spike at the proximal curvature of each palpating finger. It will easily go through to find space to expand and create a spike at the distal curvature.
The second dosha pitta, is also laghu, light but it is liquid and substantial in nature while vata is light and empty. However, because of the lightness and drava guna (liquidity) of pitta, pitta spike will be felt on middle curvature of each of the three fingers.
Kapha is guru ( heavy), sthira ( static) and Manda (slow). Because of these qualities, kapha stops at the site on the finger closest to the heart and creates a spike at the proximal curvature.
For diagnostic purpose, The scheme of pulse daignosis is divided into seven levels. It include Vikruthi pulse ( disbalances in internal organs ), Manas vikruthi ( disbalance in psyche ), Sub doha prakruthi ( for understanding subtypes of doshas ), Ojus - Tejas- Prana pulse ( Vitality, Enthusiasm and life), Dhatu pulse ( for understanding the functions of tissues, Mana prakruthi ( Psychological ), and also there is prakruthi (General body Constitution ). In first level ie Vikruthi, all the three fingers has to feel all the doshas, that means each fingers will have vata, pitta and kapha spikes. For example, if we take the index finger, the distal curvature will be vata, middle region will be pitta and proximal curvature will be for vata spike. Mana prakruthi at the second level will also have such an order of doshic spikes. The detailed analysis of each point is out of the scope of our brief discussion.
We have discussed the spikes of Vata, pitta and kapha and how they manifest through the pulse. It is convenient to divide the reading of the radial pulse into seven levels. But at this point we will move our attention to Prakruthi and vikruthi and how to read them on the seventh and first levels of radial pulse. To avoid confusion, be aware that the location of Prakruthi and vikruthi are referred to in several ways- levels seven and one, deep and superficial, balance and imbalance. Prakruthi is one's basic constitution, established at the time of conception, and is read at the seventh, the deepest level. Vikruthi is our present state and is read on first superficial level of the pulses. When deep pulse corresponds to the superficial pulse, that person is healthy and balanced. Once the Vikruthi is understood correctly then the physician can move to other levels like mana prakruthi, sub doshic level, organ pulse etc..
The Ayurvedic art of learning is more than mechanical or technical. Technique is a small part, but perception, sensitive observation and awareness are very important. For example, when you and I look at an object, we look from different angles. When our perception is on the same level, at the same time, with the same intensity and on the same platform, then we will perceive the same object and our observations will go hand in hand. However, there will still be personal differences. That doesn’t mean that one person is wrong but, in the case of reading the pulse, that person may be on a different level. Prakruthi pulse is the seventh level and if one examiner comes only to the sixth level, readings will be different. Even though there are differences of perception, its possible that two examiners may be reading the pulse at different levels. So, all it takes is a continuous practice and sensitivity to feel the spikes very precisely so that it will help the physician to arrive at a proper diagnosis.
In present scientific advancement, we have so many diagnostic tools to understand the pathology. But the relevance of pulse diagnosis is really helpful to arrive at a doshic level understanding of the condition so that the physicians can select the drugs more accurately to treat it.