Pranayama is a compound word in Sanskrit composed of ‘prana’ + ‘ayama’. Prana is the cosmic/universal life force which is responsible for keeping us ‘alive’. In India, when a person dies, we say that ‘prana’ has left the person’s body. The word ‘ayama’ has two different meanings – to stretch/elongate/expand and to control/restrain. Breath is a gross manifestation of this prana. So, the word pranayama means the ability to expand or stretch our life force (prana) by controlling the breath. Pranayama techniques involve controlling the breath in a variety of ways. According to Sage Patanjali (sutra 2.50), “Modifications of the breath are either internal, external or stopped; they are to be regulated by space, time and number and are either long or short”. In this context space represents either a specific point of focus within the body (e.g. lower spine) or the left/right nostril, time means the duration of the breath and number means the number of inhalations and exhalations or retentions. Following these guidelines, a large number of breathing techniques have been documented in the Hatha Yoga Pradeepika, the ancient text on Hatha Yoga. Pranayama is the fourth of the eight limbs of yoga (Ashtanga Yoga) as defined by Sage Patanjali. It provides a vital bridge between the body and the mind. By controlling the breath, one can control the mind. When a person is angry or agitated, his breath is fast, disturbed and shallow. When a person is calm, his breath is soft and undisturbed. We often hear the phrase, “take a deep breath!” whenever we are upset over something. What yoga teaches us is that not only our emotions control the quality of our breath, but we can control the mind and our emotions by controlling the breath.