Nadi is a tubular organ of the body like an artery or a vein for the passage of prana or energy. A nadi has three layers like an insulated electric wire. The innermost layer is called Sira, the middle layer damani, and entire organ, as well as the outer layer, is called nadi.

Sodhana meaning is purifying or cleaning, pm the object of nadi sodhana pranayama is the purification of the nerves. A jittery obstruction in a water pipe can cut off the supply entirely. A little obstruction in the nerves can cause significant discomfort and paralysis a limb or organ.
How to Perform
1. Sit in Padmasana
2. Keep the spine erect and your head and neck straight
3. Your eyes should be closed
4. Relax the muscles of the body and become aware of your breath
5. At no point during the exercise should the breath be controlled or forced
6. If you find the Padmasana pose difficult to maintain, you can practice Nadi Suddhi breathing seated on a chair. It is important to make sure that your feet are on the floor, and your back is straight throughout the time you are in this posture.
7. With one hand, let your fingers stretch and bend your index and your middle fingers and place them on the palm of your hand.
8. Put the thumb on one nostril and the tip of the ring finger against the other nostril.
9. The thumb and ring finger will be used to close alternate nostrils as you breathe.
10. Begin the exercise by blocking your left side nostril and breathe out through your right nostril.
11. Continue to block your left nostril and breathe in using your right nostril.
12. Open your left nostril as you simultaneously cover and block your right nostril. Breathe out slowly using the open left nostril.
13. Once this is done go ahead and breathe in with your left nostril that is open.
14. Close the left nostril and let the air move out through your right nostril that you now leave
open.
15. This is considered one cycle. The breathing should be slow and rhythmic.
16. Continue breathing this way by opening and closing left and right nostrils and complete ten cycles to begin with.
17. As you advance in your practice, you can increase the duration of each cycle and the number of repetitions.
As a beginner, Nadi Suddhi pranayama can take a great deal of practice and concentration to master. Try and focus on the breath to prevent the mind from wandering.
Duration:
Ideally, at least 18 to 30 rounds of Alternate Nostril breathing should be performed to maximize the benefits.
Benefits:
1.As pure oxygenated air is breathed into the lungs with each cycle, the Blood gets purified
, and circulation improves.
2.This pranayama helps strengthen the lungs and increases overall lung capacity.
3.Alternate Nostril breathing can help treat disorders of the respiratory system.
4.Due to the improvement in blood circulation, functioning of other organs in the body also
improves.
5.As circulation improves, energy levels also increase.
6.Nadi Suddhi pranayama can help with weight loss as it increases the rate of metabolism.
7.It helps calm the nervous system.
8.Regular practice helps reduce stress.
9.It can improve mental health.
10.Alternate Nostril breathing can help remove excess body heat.
11.It can help improve appetite.
12.Alternate Nostril breathing can help reduce odor.
13.This type of pranayama breathing is believed to strengthen the immune system and prevent illnesses.
Precautions:
1.The effects of pranayama breathing on theorgans are almost instantaneous.
2.Therefore it is extremely important, to practice pranayama breathing exercises only under the supervision
and guidance of a trained yoga instructor.
3.There should be no forced or strained breathing during the exercise, as this can
prove harmful to the body.
4.If during the exercise, you feel your body shaking involuntarily or that your muscles have become tense, stop the exercise and breathe normally.
5.If you suffer from high blood pressure, you should avoid Alternate Nostril breathing.