According to yogic physiology and philosophy, three main nadis exist within the frame of the spinal column - ida, pingala and sushumna. Ida and pingala are responsible for the two sides of human nature coexisting within every individual. Ida is the introverted, mental side of our personality and represents the lunar, subjective and receptive aspect of our being. When the flow of prana in ida nadi is predominant, mentality predominates over vitality, and the jnanendriyas (organs of outer knowledge or sensory input, the eyes, ears, nose, tongue and skin) are activated. Pingala nadi corresponds to the extroverted, expressive side of the personality, and represents our solar, dynamic and objective aspect. When the prana flows predominantly in pingala nadi, vitality predominates over mentality, and the karmendriyas (motor organs or organs of action, the hands, feet, sexual organs, anus and vocal cords) are activated. Symbolically, ida can be understood as the receptive, feminine side of our being and pingala as its masculine, expressive counterpart.
Swara yoga concerns the realisation of man's essential nature as the balance between these dual and complementary polarities. According to swara yoga, the flow of prana in ida nadi is equilibrated with the flow of breath in the left nostril, and the flow of prana in pingala nadi is similarly related to the breath in the right nostril.
The third nadi is sushumna and prana is induced to flow in this nadi only when ida and pingala, the mental and vital sides of the personality, are functioning in perfect balance. This can only occur when an equal volume of breath is moving in and out of each nostril. At that time, the awareness is neither introverted nor extroverted, but remains balanced between the two. This is when sushumna nadi flows and the state of meditation (dhyana) dawns effortlessly.
While there is inequality of the flow of breath in the nostrils, meditation will not supervene, and this is the case in our daily lives. A large experimental study held at Kaivalyadhama, Lonavala, has verified that the flow of the breath through each nostril is rarely equal under normal circumstances.*1 Of 204 subjects, aged from 10 to 65 years, and enjoying good general health, who were investigated at different times of the day, an unequal flow of breath in the nostrils was noted in 174, or 85.5% of cases.
This finding accords with swara yoga, where it is claimed that the breath alternates cyclically from one nostril to the other approximately every 90 minutes, and this can be readily verified by personal observation. There is a period of 3 or 4 minutes in each 90 minute cycle when the breath crosses over from one side to the other. In this short period, both nostrils flow equally, and this is the period traditionally advocated for successful spontaneous meditation.
Many of the practices of swara yoga, including nadi shodhana pranayama, jala and sutra neti and use of the yoga danda, directly influence the balance of breath in each nostril, inducing sushumna nadi to flow and meditation to supervene.
The dual nature of the human psycho physiological framework is reflected in the very physical structure of man's brain and central nervous system. Neurophysiological and psychological research studies have been able to demonstrate clearly that the two hemispheres of the brain are actually responsible for different abilities and characteristic modes of expression of human individuality.
The right hemisphere has been found to assume responsibility for the holistic, intuitional and psychic side of our perception which are ida nadi functions, while the left hemisphere has been found responsible for our logical, rational and analytic faculties and sequential and linear modes of thought - all pingala nadi functions. Further, the left sensory and motor cortex regions of the brain are known to be responsible for the movement and sensation of the right side of the body, while the right cortex assumes responsibility for the left side of the body. This reciprocal innervation occurs via the ascending sensory and descending motor nerve tracts, which cross over to the right side of the midline within the brainstem and spinal cord.
In terms of swara yoga, therefore, the right side of the brain is activated when the left nostril is flowing; the left brain is activated when the right nostril flows, and whenever both nostrils flow equally, every faculty of the human brain is functioning in an optimal and integrated manner as sushumna nadi awakens. Then meditation is directly experienced.
A number of research and clinical studies have verified the efficacy of the practices of swara yoga. Scientists have long known that two eyes are absolutely necessary for stereoscopic, three dimensional vision. Similarly, two ears are needed to precisely locate the source and direction of sounds, and two vestibular organs are necessary to give an adequate sense of position and balance.
The question of why man possesses two nostrils seems to have never been considered serious enough to warrant further investigation.
This false conclusion can be understood when we consider that the breath flows as two separate columns for only the length of the nostrils (4-5cms), before mixing together in the nasopharynx at the back of the nasal cavity. It then flows as a single column of air down the trachea and larynx towards the lungs. In this light, the individual flow for a few inches along each nostril does not seem, on the surface, to be important.
Various studies, beginning early last century have queried this. Most recently, the work of Dr. I.N. Riga, an ear, nose and throat specialist of Bucharest, Romania, deserves comment.*2 In a study of nearly 400 patients suffering from one-sided nasal obstruction due to distortions and malformations of the median nasal septum present since birth, Dr. Riga found that those patients whose breath flowed predominantly via the left nostril (89% of cases), suffered a higher than average incidence of a wide variety of respiratory disorders, including chronic muco-purulent sinusitis, middle and inner ear infections, partial or total loss of senses of smell, hearing and taste, recurrent pharyngitis, laryngitis and tonsillitis, chronic bronchitis and bronchiectasis.
In addition, he found that sufferers from this syndrome were more likely to suffer from one or more of a wide variety of more distant disorders, including amnesia, intellectual weakness, headaches, hyperthyroidism (with associated irritability), cardiopulmonary weakness (manifesting in palpitations, asthma-like attacks and chronic heart failure), insufficiency of liver and gallbladder (with varied symptoms), persistently altered cellular constituents of the blood and lymphatic fluid, chronic gastritis and enterocolitis (with symptoms of heartburn, gastric reflux, peptic ulcer and constipation), and sexual and reproductive disorders (symptoms of diminution of libido, ovarian irregularities and diminished virility).
In contrast, patients whose breath flowed predominantly through the right nostril, (26% of the cases studied) were found to be predisposed to arterial hypertension and its numerous consequences.
While this study is suggestive rather than conclusive, and is open to criticism in several areas, it largely agrees with the experimental observations of a large number of doctors and physicians, who, as early as 1819, were drawing attention to the state of general physical and mental health in relation to the patency of the nasal passages and their sensitive lining of mucus membrane.
Several physicians have observed a close relationship between the state of the nasal mucus lining and genital and reproductive functions. Endriss recorded his clinical observations that complementary and unexplained nose bleeding accompanied the menstrual period in some female patients, while MacKenzie observed that his patients developed a heightened sense of smell during the menstrual period. In 1929, another worker, Karpow, surgically removed the folds of nasal mucus membrane from 40 different animal species, including hares, dogs and guinea pigs, and found that it resulted in the cessation of sexual maturation in young animals. On the other hand, he found that by crushing the extracts of mucus membranes and administering it to female guinea pigs, muscular activity of the uterus was induced.
Other studies have described the interdependence of the whole territory of innervation of the trigeminal (5th cranial) nerve, which includes the face, nose, eyes, sinuses, chin and jaw, with the well-being of the whole organism. Maspetiol and Maduro described cases of intestinal haemorrhage in children following removal of the tonsillar tissues. When Reilly injected a deposit of natural body lipid (oil) into the soft palate of experimental animals, he found evidence later on that they had suffered from unexplained bleeding into the abdominal cavity at the time of the injection. In the light of these and the many further studies and research reports cited in Dr. Riga's paper, it becomes clear that patent nostrils and healthy mucus membranes are important in the maintenance of optimal physical and mental health.
Several workers have attempted to define the exact mechanisms by which the nasal membranes exert such a profound influence upon distant organs and bodily functions.
Bonnet proposed a theory of reflex centrotherapy and illustrated reflex nerve connections between the nasal membranes and other body areas, based upon a detailed, clinical study of the case histories of many patients.
Bidder and Volkmann's work demonstrated the extremely rich and sensitive innervation of the nasal membranes. They were able to demonstrate the presence of twenty times more autonomic nerve fibers within this membrane than are to be found in the cerebrospinal (central nervous) system.
This suggests that the autonomic nervous system, and its two complementary components- the excitatory sympathetic nervous system (pingala nadi) and the relaxatory parasympathetic nervous system (ida nadi) are centrally activated from the nasal mucus membrane region as well as from the sympathetic and parasympathetic nuclei lying within the brain itself. Sohier-Bryant actually defined the whole region of the nasal mucus membrane as a distinct organ of the autonomic nervous system.
It is believed that during inhalation, the flow of air in each nostril stimulates specific unilateral autonomic nerve centres lying within and beneath the mucus membranes. These specific stimuli subsequently influence the autonomic processes of respiration, circulation, digestion and so on.
In this light, we can begin to anticipate the far reaching effects of yogic practices such as neti kriya and nadi shodhana pranayama upon the whole autonomic nervous system and thence the endocrine and physiological functions.
The region of the nasal mucus membrane is also extremely important in the Chinese healing system known as acupuncture. In acupuncture therapy the 'ki' or pranic energy flowing within well-defined meridians or channels of the pranic and etheric body, is altered and adjusted by manipulating the system of fluid filled connective tissue spaces known as meridians within the physical body.
Recent studies by Dr. Hiroshi Motoyama of Japan have electro physiologically verified the existence and location of the meridians as a distinct psycho physiological communications and transmission system, functioning independently of the nervous and circulatory conducting systems.*3
Furthermore there is marked similarity and correspondence between maps of the acupuncture meridians and the ancient descriptions of the course of the major nadis or 'pranic pathways', as described in the ancient Upanishads of India.*4
Of the twelve major meridians of acupuncture, six (stomach, bladder, gallbladder, large intestine, small intestine and triple heater) have either their points of entry or of exit in the area of trigeminal nerve innervation which surrounds the nasal mucus membrane.*5
An electronasographic study carried out at Kaivalyadhama Institute, Lonavala, India, discovered that changes of electrical potential are continually occurring within the mucus membrane of each nostril.*6
These changes were found to be unequal in the two nostrils, and are believed to be influenced by a subject's psycho physiological state, as reflected in his breathing. This nasal potential is constantly changing in the same way that the human "aura" has been seen to change continually, when photographed using high voltage Kirlian techniques. This "aura" has been observed to be in a state of constant flux, responding instantaneously to the ever changing thoughts, emotions and physiological functions of the individual, and is thought by some to be a reflection of the pranic body in an electric field.
The research workers of Kaivalyadhama Institute, Lonavala, have also validated the efficacy of the ancient device known as the yoga danda or rod, which is traditionally used by yogis to manipulate the flow of the breath in the nostrils.*7
The danda is fashioned of suitable length to pass from the ground to the armpit of the meditating individual. The ancient yogis found that by leaning slightly upon this rod and applying sustained pressure in one armpit the flow of breath in the opposite nostril is enhanced. They utilised this principle during meditation practices to maintain balance between the two nostrils, equilibrating the flows of ida and pingala nadis, so that sushumna might remain open and successful meditation continue.
The Lonavala study verified that the breath in the nostril opposite to the yoga danda became markedly more free than that of the nostril of the same side in all subjects, irrespective of age and sex.
For the average person, the whole brain functions optimally only for the few moments when sushumna awakens every 1½ hours of the automatic breathing cycle. Proper use of the yoga danda, however, induces a continuing balance of both nostrils, enabling the yogis who follow the paths of tantra and swara yoga to maintain the flow of sushumna nadi and thereby experience meditative awareness for hours or days continually.
It is said that in the unaware individual, the flow of prana in pingala nadi predominates during the day, while ida predominates at night. Those who purify the network of nadis through yoga, induce ida to flow during the day and pingala at night.
However, the natural, cyclical rhythm cannot be easily broken. The five tattwas (elements) have to be first realised, and then purified. In kundalini yoga, each element is associated with a chakra or psychic centre, and these centres must be awakened.
What is the significance of the ancient science of swara yoga for the modern man or woman?
Firstly, swara yoga is a direct way of learning more about ourselves. Everyone can become aware of the state of his breath in relation to his various ' daily activities, states of mind and feelings, no matter how busy he is. In swara yoga, this sadhana alone can lead directly to sushumna awakening and entry into dhyana.
Secondly the health and optimal function of the body and mind is enhanced via the powerful autonomic nervous influence of nadi shodhana pranayama and neti kriya. These practices release daily accumulated psychic and nervous stress, which imbalances the autonomic nervous system and blocks pranic energy flow, locking it within fixed configurations and circuits. Over long periods of time, these pranic abnormalities and disturbances, if remaining unreleased, result in the whole gamut of psychosomatic and stress-related diseases which we as individuals and communities are confronted with today.
Swara yoga is one most effective way to develop continuity of consciousness in both the gross and subtle planes and to acquire homogeneous awareness throughout the waking, sleeping and dreaming states. It is a path which leads to dhyana in the midst of an active life in the world.