Yoga is a complete science of health, which deals with the understanding of the adequate functioning of all systems of our body and appropriate coordination between them, along with the healthy functioning of our mind. It differs from the western medicine in the sense that this system deals basically with the disease, its diagnosis and treatment. The techniques of yoga are designed in such a way that they not only maintain but also enhance the potentiality of body parts, which yield good health, vitality, disease-free and lasting youthfulness.
Regular practice of yoga not only keeps the body healthy and fit, but also prevents either of the physical, mental and emotional imbalances due to various reasons in our day-to-day life. In natural state, if all components of the body perform their functions adequately, that will be termed as state of health. In case of any disorder and abnormality every such part works to restore the health. A device that promotes such restoration phenomena may prove to be of great importance. Yoga is foremost of them.
There are three major subdivisions in the structural organisation of the body. First subdivision, known as ‘infrastructural group’, includes skeleton, muscular and integumentary systems; the second subdivision, known as ‘control group’, includes nervous and endocrine systems, and the third subdivision is termed ‘maintenance group’, which includes the remaining systems, viz. respiratory system, digestive system, excretory system, cardiovascular system, immune system, lymphatic system and reproductive system. In the state of health, in spite of a number of variations in their structure, all these systems work in very balanced coordination. Yoga works systematically on all these systems to keep them functioning in better balance and perfect condition.
Much of the illness and loss of vitality are the result of bodily abuses, which we undertake knowingly or unknowingly. In today’s mechanised life we spend long hours without proper air, sunlight, adequate sleep, adequate relaxation and stretching various body parts, balanced diet and planned activities, which leads to unending series of troubles and ailments. Yoga can do much more to restore normal biological, biochemical and mechanical activities of body systems, even after quite unhealthy life style for years together.
Yoga philosophy has very vast dimension, and physical body is only one aspect. Mind and spirit are other equally vital aspects of complete health. Yoga always pays attention to integrate the functions of mind, body and spirit. According to ancient Indian philosophy there are five “sheaths” to human existence. The first and the innermost is physical body; the second is the vital body, known as Prana, through which vital energy flows throughout the nadis; the third sheath is known as mind, which is the seat of emotions and thoughts; fourth sheath is of perfect thought and knowledge, termed intellect; and the last and outermost sheath is known as ‘bliss’, which includes universal consciousness.
Different diseases and disorders originate in the imbalance in these sheaths of existence. In the first three sheaths, i.e. physical, prana and mind, ego consciousness predominates and therefore harmony in these sheaths can be easily disturbed. The fourth and fifth sheaths are parapeted by a wider, universal consciousness and cannot be permeated. When a person is truly healthy, the positive energy in the highest sheath percolates freely through the lower ones and brings total harmony and balance to all his faculties. But though the harmony of the higher sheaths is constant, the free movement of bliss can be blocked by imbalances in lower sheaths. (— Dr R. Nagrathna, Dr H. R. Nagendra and Dr R. Monro).