Introduction:
Regular meditation practice is an efficient tool, both for heating and maintaining good health. Modern scientific research has now established that there is no denying the fact that sick people do get well by harnessing the psychic forces through mental imagery. In fact, a new discipline called psycho-neuro-immnuriology has entered the field of modern research. The body's natural defence mechanisms against infection,con-tagions,toxicity and other pathological disorders constitute the immune system of the body. Immunology, thus, means scientific study of body's defences and resistance to infection etc. The new discipline, therefore, is the study of inter-relations between the immune system, the brain and the psychical forces probably hidden in the subconscious portion of the mind
Innate Immunity
Lymphocytes are the principal cells of the innate immune system. They operate is close association with the phagocytes which can engulf and inactivate microorganisms. The bone marrow the thymus, spleen and some lymphoid nodules produce the lymphocytes. The production, activation and immune response is a highly complex process involving finely balanced relationships between many organs of the body.
Neuro-immunologists have, after elaborate study of men under stress, established that the immunity can be seriously affected by one's mood and attitudes, and there is a significant lowering in the functioning of the system under stress. Conversely, deep relaxation and sustained cheerfulness improve both the qualitative and quantitative efficiency of the system.

Apart from the researchers many eminent doctors as well as general practitioners agree that meditation and deep relaxation can cure and prevent any number of psychosomatic diseases. Concentrated perception of body - "Sarira Preksa" produces a more balanced equilibrium between the sympathetic and parasym-pathetic components of the autonomic nervous system, which is ultimately responsible for the homeostasis in the body.
Improvement of physical health without the use of injurious drug, though a valuable benefit, is not the chief objective of meditation It is a tool for awakening and developing one's conscious reasoning and thereby modifying one's attitude and behaviour to be truly worthy of a human being.
Deep-level consciousness is an innate aspect of human wisdom and has an elevating effect on human personality. Unfortunately, the modern way of life has considerably weakened this ability and one has come to believe that he can function satisfactorily without awakening and activating the inherent deep-conscious abilities.

To become acquainted with one's own body is an essential medium of spiritual advancement and self-awareness. Perception of body is a technique of becoming acquainted not only with the gross physical body but also with the mysteries of the subtle (taijasa) body and the super subtle body (karma-sarira). After this, it is not difficult for the practitioner to reach and be acquainted with his deep-level consciousness. On the other hand if one thinks that one could reach the spiritual self without properly understanding the significance of the flow of vital energy in different parts of the body, it would be a mere imaginary achievement.

Practice of perception of body is, thus, an essential step for acquiring not only physical goodness but psychical goodness also.