Prana

Prana (Sanskrit प्राण, prāṇa — "life force", "the breath of life") is the universal life energy of the Indian tradition, pervading all living beings.

Sources. The concept appears in the Upanishads, Ayurveda (#19), Yoga and tantric systems — it is a basic category of all Indian physiology.

The Five Main Kinds of Prana (Pancha Prana, पञ्चप्राण)

• Prana (प्राण) — rising breath. Region of the heart, inhalation, perception.
• Apana (अपान) — descending breath. Region of the pelvis, exhalation, elimination.
• Samana (समान) — balancing. Region of the navel, digestion, assimilation.
• Udana (उदान) — rising beyond. Region of the throat, speech, growth, the moment of death.
• Vyana (व्यान) — all-pervading. The whole body, circulation, coordination.

Circulation through the Nadis

Three main channels. Prana circulates through the Nadi system (नाडी — energy channels), the main ones being:

• Ida (इडा) — the lunar channel
• Pingala (पिङ्गला) — the solar channel
• Sushumna (सुषुम्ना) — the central channel

Pranayama

Control of breath. The practice of Pranayama (प्राणायाम — control of breath) aims at purifying the Nadis and awakening the Kundalini (T055).

Analogs in Other Cultures

• The Chinese analog — Qi (氣)
• The Japanese — Ki (気)

Difference of ontologies. Although the function is similar, the ontology differs: Prana is inseparable from the concept of Atman (आत्मन् — the eternal soul), whereas Qi is not tied to the notion of an eternal soul.