Any serious discussion about Pranayama is not complete without a reference of Nadi. The origin of the Nadi has a history behind it. It had occurred several times in all the Yogic literary works of the later period. Also in the Yoga books of Pranayama , the writers like Bhagavan Patanjali and also Vysa mentioned about Nadi.

Nadi is special anatomical structures closely identified with the nerves of modern anatomy. It is the only standard one that has been derived over the year. However , though several interpretations have been derived by all the famous Yogic scholars of ancient India, these are not at all acceptable. The standard conception that has been derived are based on mere assumption . Opinion also differs regarding the number of Nadi that are present in the body of any normal human being. What is regarded to be most authentic proof is that the number of the more significant Nadi is three and also that of the most vital one is only one. Today, efforts have been taken so that scientific evidences can support these.