How do I know when my Nadis are Purified? 
By Marion (Mugs) McConnell, ERYT500, SOYA, SYVCA, Canadian Representative for IYTA
During the immersion portion of our Yoga Teacher Trainings, we engage in a steady practice of Nadi Sodhana for two weeks, morning and evening. The purpose of this is to get established in this pranayama practice for the purpose of purifying our nadis.  A very good question came up during a study session in our training, “How do I know when my nadis are purified?”
 
My first response to the question was, “When the prana is able to go into the sushumna” but of course the next logical question that came back was “How do you know when it does that?” There are certain things that occur, like unmani avastha, a state of deep concentration where the breath stops and the mind becomes still (Hatha Yoga Pradipika Chapter 2 verse 4-10).
 
Swami Sivananda says in his book “The Science of Pranayama”, when the nadis are purified there is a “lightness of the body, brilliancy in complexion, increase of the gastric fire, leanness of the body, and the absence of restlessness”.  He says in the first stage of purification perspiration arises without effort, the middle stage is the tremor of the body, and the last stage is levitation in the air” (or in a broader sense, siddhis begin to appear).
 
When you do a cleansing fast, you really notice the difference in how you feel during and after the fast. It is difficult at first, and you may feel rather ill as the toxins are cleaned out.  As time passes, you begin to feel lighter and brighter and terrific!  It is similar when you do yoga practices to cleanse the nadis.  At the start you may not feel too well as blockages begin to release.  Blockages in the nadis often manifest themselves physically, so you may feel symptoms such as headaches, emotionally off balance, or one nasal passage becomes blocked.
 
Gradually, over time through the cleanse you have more energy and more clarity too. You feel good about yourself and your discipline and the results are generally quite delicious. There is a peacefulness that comes with the cleansing of the nadis because the thoughts are no longer jumping between the right and left brain… the union of “ha” and “tha” has brought this into balance and we experience santosha or contentment.
 
But nadis can become impure again if you, for example, reinstate junk food into your body, smoke, allow negative thoughts to run untamed, or cultivate ill intentions. So the nadis don’t necessarily stay purified if you don’t keep up your practice on all levels, on and off the mat.
 
When we do our yoga we are working with more than the physical body. Our sadhana also affects the astral body (which includes the emotional and mental aspects of our being), and the causal body (which involves our spiritual well- being).  Each layer of maya we uncover takes us closer to another vritti or samskara to perhaps deal with. As we change and develop our thought patterns through our yoga practices (ie: how we respond to new circumstances) they reflect the cleanliness of our nadis.  Pure thoughts = pure nadis, and negative thoughts such as fear or anger = not so clean nadis.
 
In Chapter 2 verse 4-10 in the Hatha Yoga Pradipika we discuss the cleansing of the nadis.
 
Nadis(4) When the nadis are impure, breath cannot penetrate into the sushumna. Then the yogi achieves nothing, nor can he reach the state of deep concentration [unmani avastha].
If there are blockages in our 72,000 nadis then the prana, or life force, is impeded in its flow.  Nadis are the energy channels for the flow of prana, the life force that brings movement to our bodies and thoughts.  The chakras are transmitters of this energy, and they have the potential to transmit both positive and negative energy depending upon where our thoughts and behaviours are centered.  Therefore, this energy is expressed or manifested in our outward actions through our body.
I often say “I see myself through the reactions of others towards me.”  If I am angry or annoyed, this will create a reaction in others that reflects my state of mind. If I am angry or annoyed, I am distracted (attachment) and I cannot concentrate.  My state of mind is a reflection of how purified my nadis are.  As yogis we are constantly trying to live a higher life and increase the supply of prana through the nadis to the sushumna. Only then will we feel peaceful and therefore be able to reach the state of deep concentration.
(5) Only when all the nadis, which are still impure, become purified can the yogi practice pranayama successfully.
(6) Therefore one should practice pranayama with the mind in sattvic condition until the sushumna is free from impurities.
Here we are back to the basics of the yamas and niyamas.  A sattvic mind is essential for success in ALL practices of yoga, and definitely during the practice of pranayama.  Pranayama is the ability to control the movement of the life force. It establishes intention and focus.  A wandering mind means the prana is being dissipated away from the task at hand – yoga or union with the Self.
A sattvic mind is reflected in our outward expressions through our body.  Kindness, compassion, understanding, patience, a peaceful presence, loving actions; these are all outward expressions of a sattvic mind.  By practicing the positive expression of your True Self regularly, steadily, and catching those negative thoughts before they get a chance to have any power, it will help you to maintain the sattvic state of mind, particularly during pranayama.
Sattva must become established in thought, word and deed. This may seem like far too much of a challenge, but we are given the tools to change our thought-waves from negative to positive in Patanjali’s yoga sutras where we discover the mind is made up of “manas, buddhi and ahamkara”.  Manas is that which records the incoming information from the senses.  Buddhi is that which classifies this information as truth, untruth, etc.  Buddhi is normally clouded by the ego, the ahamkara, and therefore classifies information under the influence of the ego.  This is because we are more in tune with our “ego-personality” than we are with our Spirit.
The Spirit is rich with the qualities of love, peace, compassion, non-judgment, etc. The ego-personality has the potential of both positive and negative qualities because it is in this manifested world.  Therefore, we must establish the habit that each time the mind receives information through the senses, we pause before judgment. We don’t make assumptions, we don’t jump to conclusions, but we filter the information based on the higher principles of yoga beyond the ego, and then classify the information according to the principles of the Spirit.
Let me give you an example.  An older couple lived in my community.  The wife passes away in the fall, and I went to Mexico for the winter.  When I returned, I was walking by the man’s home and saw a woman going in the front door. I immediately assumed he had remarried.
Recognizing my quick assumption, I immediately stopped the thought wave of him being remarried to further assess the situation before I jumped to conclusions.  She could have been his sister, housekeeper, friend… there were numerous options!
Manas had recorded what it had “seen” through the eyes (senses).  My ahamkara “ego-personality” immediately influenced the buddhi to classify this information based on the assumption the man had remarried.  I caught myself by observing my thought waves, and thus stopped the influence from the ego-personality, allowing the buddhi to reclassify the information as based on no truth whatsoever.
Simple example of how we control our thought-waves. Not a very important situation (and really none of my business), but this is how our mind works! So by putting this process of observation into practice on the little things like this will create a new standard of observation for when we encounter the bigger, more important circumstances in life where we really need to see things “clearly”!  No matter how unimportant the circumstances may seem, it is always important to establish yourself in Truth, sattva, a pure mind.
Yoga is the control of thought waves in the mind. To emphasize how important this is for our yoga practice and the purification of the nadis, I quote from Yoga-Age.com, “If we now become aware that every breath we take is in a sense pranayama, we can readily realize how frequently we damage our delicate psyche with an impure or bad thought. In the long run we shorten our lives with every negative gesture in deed, word, or thought by overburdening the conductors of the life stream with these impurities.”
Now, for the last few verses in the Hatha Yoga Pradipika on the process for cleansing the nadis:
(7) Assuming the padmasana posture, the yogi shall guide the prana through the left nostril [chandra = moon] to the ida nadi, and, after having retained the breath as long as possible [in kumbhaka], should exhale it through the right nostril [surya = sun].
(8) Then he should inhale through the right nostril, do kumbhaka according to the rule, and exhale through the left nostril.
(9) Inhalation is [always] through the same nostril as the previous exhalation. After the breath has been retained to the utmost possible limit [until perspiration breaks out or the body begins to trembler, one should exhale slowly–never quickly [since that reduces the energy of the body].
(10) Take in prana through the ida nadi and exhale it through the pingala. Then take in [new prana] through pingala and release it through ida, after having held it [in kumbhaka] as long as possible. The yogi who has perfected himself in the yamas [having thus developed the sattvic mind] will purify his nadis in three months [of practice].
So, how do you know if your nadis are purified?  Watch your thoughts and watch your actions, and they will reflect exactly how purified your nadis are. And remember these wise words from the Katha Upanishad, “When the five senses and the mind are still, and reason itself rests in silence, then begins the Path Supreme.  This calm steadiness of the senses is called Yoga.  Then one should become watchful, because Yoga comes and goes.” 
Resources:
Hatha Yoga Pradipika, commentary by Swami Vishnudevananda
How to Know God, The Yoga Aphorisms of Patanjali, commentary by Swami Prabhavananda and Christopher Isherwood
The Science of Pranayama, by Swami Sivananda
The Upanishads, commentary by Juan Mascaro
Yoga-Age.com