Nadi means “flow”. Nadis are subtle flows of energy. They are a dense network of of entirely subtle energy channels which provide energy to every cell throughout the entire body. Hatha Yoga Pradipika and Goraksha Samhita quote 72,000 nadis in the body whereas Shiva Samhita states 350,000 nadis arise from the navel center. These nadis are depicted like tiny threads hanging off the spinal cord very much like in the nervous system where nerves coming off the spinal cord transmit nerve impulses thrughout the body. Because they are subtle energy flow channels, you will not be able to see the nadis like you see the nerves when you dissect the tissues.
There are ten major nadis, out of which three are the most significant. The three are – Pingala, Ida and Sushumna. They are the three main channels for the distribution of energy throughout the entire pranic network. They are like high voltage wires.
According to yogic physiology and philosophy, they exist within the spinal column. Ida and Pingala are responsible for the two sides of human nature which exist in each human being. ida is the mental, introverted, receptive, feminine side, chandra -the lunar side, Pingala is the vital, extroverted, expressive, masculine side, surya -the solar side. Ida and pingala correspond to the parasympathetic, sympathetic and cerebrospinal nervous systems of medical science.
Pingala nadi originates in the muladhara chakra and emerges from the right side of the chakra. From here, it goes in a semicircle, going back to the center to cross ida at swadhisthana, goes to the left then curves back to center to cross ida again at manipura. It intertwines in this way, crossing ida at each of the six chakras, the last one being ajna chakra. At Ajna, it goes straight up the sushumna to sahasrara at the crown of the head. Pingala governs the right side of the body .
Pingala is known as the surya or solar nadi as the pranic energy flow has attributes associated with heat, masculine qualities, physical and mental exertion, physical vitality, tension. The effects of pingala coincide with the functions of the sympathetic nervous system. Pingala predominates during the day hours although ida also flows then.
The processes of the left t hemisphere of the brain is related to pingala; the left cerebrum controls the processing of information in a logical, linear manner. It is also responsible for rational, analytical, mathematical thinking. Thus pingala and the left cerebrum enable daytime work and thinking.
Pingala controls the annamaya and anandamaya koshas. The awareness in the deepest state of meditation and in samadhi is pingala energy. Physical vitality is pingala energy.
Ida also originates at the muladhara chakra at the base of the spine. It exits from the left side from muladhara, curves in a semicircle to swadhisthana where it crosses pingala there. It’s path is similar to pingala’s path except on opposite sides. It ends at Ajna chakra on the left side and goes straight up the sushumna to sahasrara.
Ida is representative of mental energy flow (manas). Ida nadi is also known as chandra (moon) nadi due to its association with feminine attributes, introversion, coolness, quietness, receptivity. To counterbalance pingala’s predominance in the day, ida predominates at night, is active while relaxing, reading, thinking, sleeping.
A predominance of Ida energy gives a calming effect on the body and mind. This is similar to the effects of the parasympathetic nervous system.
Ida is connected to the right side of the cerebrum of brain. The right side of the cerebrum is used more for visual and intuitive processing. Hence, ida will stimulate creative, artistic, musical abilities, mental, psychic and extrasensory perception. Ida controls the manomaya and vijnanamaya koshas. Desires, thoughts, emotions and, feelings are in the mental dimension until they become physical. Psychic and intuitive knowledge, extrasensory powers are in the ida range or energy
Sushumna nadi also originates from the base of the spine at muladhara chakra but follows a straight path up the spinal column. Sushumna represents spiritual awareness. It is the pathway which the kundalini rises. In most people, this nadi is mostly dormant with no flow or minimal flow. Prana is induced to flow in sushumna nadi only when ida and pingala, the mental and vital sides of the personality, are in perfect balance, when there is balanced flow of breath in the nostrils. The sushumna flow is dormant till a higher state of evolution or consciousness is reached. -Pingala is likened to positive change, ida, negative charge and sushumna, neutral charge.
Link between flow of breath at the major nadis
Ida and pingala dominance is directly related to the flow of breath at the nostrils. When the flow of breath is stronger in the left nostril, it means that ida is dominant and when the flow is stronger in the right nostril, pingala is predominating. When one is active, the left nostril flow will be stronger. When sushumna is active, breath flows through both nostrils simultaneously and the entire brain is active. Sushumna flows after the practice of pranayama, prayer and meditation. Only half of the brain is active in ida or pingala follow. Yogis have come up with breathing techniques to regulate the flow of ida and pingala in order to intensify the experience of the pranic body.
Sushumna represents the balance of the opposites at all levels. When energy flows in the sushumna, feelings of steadiness and, meditative states arise. New states of consciousness are experienced.
Blocks in the nadis
Blockages in the subtle nadis may be caused by the energy waves of disease, tension, mental patterns, unconscious and subconscious, negative thoughts, tamas and rajas. These blockages are subtle just like the nadis. Blockages in the nadis often manifest as disease in the annamaya kosha. The affected areas become weak due to depletion of prana in the area due to the blockage.
All yogic practices purify the nadis, through pranayama is the main technique. Pranayama purifies at the pranic level but its effects will be reflected also in the physical and mental levels. Even if one is unaware of the blocks, regular practice of pranayama clears it up and keeps the pranic circuit flowing freely