Prana is a Sanskrit word that refers to a life-sustaining force of living beings and vital energy in natural processes of the cosmic world. Prana was first explained in the Upanishad where it is part of the world ,sustaining the body and also the mind .Prana includes all the living form but it is not the atman or the individual soul .

Prana is the main concept of the traditional Indian medicine and Yoga .It flows through fine channels called the the nadis ida, the pingala, and the sushumna. Ida is the left side of the body ending at the left nostril and pingala to the right side of the body ending at the right nostril. Within the body alternate nostril breathing balances the prana .When prana enters a period of intense activity, the Yogic tradition refers to it as Pranotthana.

Prana is held to be the Breath of life and in Yoga pranayama techniques are used to control the vital energies within the body.The presence of Prana distinguishes a dead body from a living one .When a person dies the prana or life force is thought to leave the body .All physical feelings and energies that arise or flow within the body is interpreted as prana .Infact feelings of hunger ,thirst ,heat ,cold are interpreted as pranic manifestation. There are five pranas or vital currents in the Hindu system : Prana, Apana, Vyana, Udana and Samana. The pranas constitute the second sheath (kosa) of a human being (who is essentially the Atman or the Self).