Pranmay Kosh (the life force) is the pranic sheath composed of prana, the vital principle or the force that holds together the body and the mind. Its physical manifestation is the breath. As long as this vital principle exists in the organisms, life continues.
Vital energy, Prana which according to its location, movement and purpose has been divided into five major and five minor components. Yogic literature mentions the presence of 72,000 pathways along which the Prana moves in human body. The pathways have been named as Nadis in Yoga. These 72,000 Nadis interconnect the energetic centers, or chakras in human body. Even though the form of this sheath is subtle, it is very similar to the form of the physical body.
Nadis are astral tubes that carry pranic currents. They cannot be seen with the naked eye. They are not the ordinary nerves, arteries and veins. Three of them are important – Ida, Pingala, and Susumna. Susumna is the most important because Kundalini passes through this Nadi only.
The kundalini system consists of 72,000 nadis and the Sushumna, Ida and Pingala are the locations of Pranmay Kosha. Coupled with the five organs of action (hands, feet, organ of speech, organs of evacuation and the organ of generation.) it forms the vital sheath. Supreme Lord in the living symptoms or life forms.
Acupuncture, reiki and magneto-therapy seem to be working on this Kosh. Homeopathic medicines in moderate potencies (extremely high dilutions) also act on this Kosh.