In our lives we suffer; we suffer due to the body; we suffer due to the mind; we suffer due to the emotion; we suffer due to our desires; and in this way we create imbalance in our psycho-physiological structure. When this imbalance is created within us, it hampers our internal growth, This state of imbalance is also felt on the energy level.
According to Yoga, in our physiological structure there are 72,000 nerve channels which are also known as nadis. They are the conductors of our vital or psychic energy, and they have nothing to do with the nerve* of our nervous system. The nerves of the nervous system carry sensory impulses to and from the brain to the body, but the nadis are the conductors of energy, vital and psychic, and this process, takes place on the psychic and subtle levels of personality, of which we have no awareness whatsoever. Blocks are therefore created, impurities are accumulated in these channels, which hamper our systematic growths the evolutionary growth of the body, mind, thoughts, feelings, emotions, desires and consciousness. The practices that we do in Yoga are specifically designed to remove these blockages from the nadis so that the energy can flow unhampered.
There are nerve centres in our physiological structure, that control the flow of the shakti. These centres are located in our spinal cord. The first one is at the base of the spine; the second is at the sacrum area of the spine; the third is at the navel; the fourth is behind the heart; the fifth is behind the throat of the energy. Precisely in this light, many scientific experiments have been conducted to see how the practices of asana and pranayama influence the structure of our body and mind.
Yoga says that where there is harmony at the physiological level, this experience is felt by the mind, and when there is physical tension it is experienced in the mind. Conversely, when there is mental tension you can feel it in the body. In the same way when there is harmony, equilibrium and a feeling of optimum health in the body, you experience it in the brain, and you also experience it in the mind. This state eventually influences the different dormant areas of the mind, thus awakening the potential that is inherent within them. This is the concept of total health.
When we talk of health we are not talking about the health of the muscular system of the body. When we talk of health we are not talking about the alleviation of physiological problems. When we talk about health, we mean harmony, balance, equilibrium at each and every level of our personality, in each and every dimension of our personality.
When we attain this experience we achieve the state of true and complete relaxation. Our sensory perceptions become introverted. In this state of relaxation our awareness of the worldly sense objects, objectified eternal awareness, is also introverted. We have been aware of the external experiences but we have not been aware of the internal experiences, and the aim of Yoga is to make you aware of internal experiences. It is to make you aware of both realities, external and internal, which in turn helps you to transcend or understand your own capacities, limitations and potentials. Therefore Yoga is considered to be a science of the body, of the mind and of the spirit; it is a science of the total health of the whole of our being.