In stress-related disorders both psychosomatic and somato-psychic factors are operating. Stress produces disease in a psychosomatic way, from mind to body, and the effects of disease again travel back to the mind via DIAFS (Disease Induced Anxiety and Fear Syndrome). The effects of stress travel to the body and back again to the mind, leading to a vicious cycle, which worsens the state of the patient. However, with the practices of yoga, we are able to put a brake on this vicious cycle and prevent further deterioration.
Yoga is very effective in stress-related disorders and in many cases it proves to be the only method of relief. However, a scientifically validated link is still missing between the hypothesis of yoga, on the one hand, and its effects, on the other. Efforts are being made to find this scientific link. There is a great deal of evidence available and clues which point to the direction in which the two can be linked, to see how the hypothesized pathways operate to produce amelioration of disease of the human psychophysiological system.
All disease has an inherent psychological component. Even the incidence of ischemic heart disease, which has reached a catastrophic level, is a condition of this mind-body complex. Busy stressed professionals are all at risk of cardiovascular accidents and ischemic heart disease, which are the major killers in the West. We know that the syndrome of angina leads to myocardial infraction because the coronary arteries either develop atherosclerotic plugs, or there is spasm or thrombus formation in the coronaries. When we try to find out the causes, modern science tells us that they are all due to underlying metabolic problems, mainly hyperlipidaemia, hypercholesterolaemia, the risk factors of diabetes, obesity, hypertension, etc. All these factors lead to accelerated atherosclerosis.
However, one question remains unanswered: where do hypercholesterolaemia and hypertension come into the picture, and how do these metabolic problems arise? There are hundreds of major and minor neurotransmitters, hormones, growth factors, etc. circulating constantly in our bodies. There are many chemicals, such as angiotensin or cortisol or adrenaline, influencing each and every cell. Normally they are secreted in regulated quantities and rhythms. When these quantities and rhythms are disturbed, a metabolic defect is produced in the whole body. This metabolic defect is an outcome of a disturbance in the endocrinal tuning. This endocrinal orchestra, not only of the major endocrinal secretions, but also of the minor endocrinal secretions, no longer remains harmoniously tuned but becomes a jarring chaotic noise.
These endocrinal metabolic phenomena are closely related to the activities of the autonomic nervous system. We know that the brain centres, which control the autonomic and endocrinal systems, are in the pineal-pituitary-hypothalamus complex, which is situated in the centre of the brain. The incoherent and chaotic impulses generated in the control station are responsible for throwing the whole balance of internal homeostasis out of tune.
The hypothalamus is an integral part of the limbic system, and the limbic system is the seat of emotional reaction. This shows the link that exists between the emotions and control of bodily functions. Any conscious or subconscious emotional conflict, tension, anxiety or insecurity affects the neurotransmitter balance in the limbic system, and this, in turn, transfers the stress-related problems down into the hypothalamus, disturbing the hypothalamic balance at some point.
Since the hypothalamus is the highest autonomic and endocrinal control centre, the chaotic impulses travel via the sympathetic and parasympathetic nervous systems, on the one hand, and via the pineal-pituitary complex into the endocrinal system, on the other hand, finally affecting each cell of the body.
The cells are fabulous machines created by nature, full of intelligence, that can carry out hundreds of distinct chemical reactions within the space of a needle tip. They are very sensitive to the minutest change in their environment and respond to the subtlest alteration in hormonal and chemical balance. Depending on the type of imbalance, different cells, tissues and organs respond differently, either by developing malfunctions, extra growths, disturbed immunological behaviour, and so on.
Ultimately, most bodily dysfunctions can be traced to mental afflictions, which travel via the brain centres into the body. Therefore, it is not possible to segregate the root causes of different diseases. They all share common roots that lie somewhere in the unknown depths of the mind. Yoga has always said that it is not possible to pinpoint separate causes for separately labelled diseases. All diseases are different shoots of a single psychosomatic syndrome.
Recent medical journals say that hypertension, diabetes, heart problems and hyperlipidaemia are not different diseases, but are part of a single syndrome. These problems represent different points in a single spectrum of disorders. Lipid abnormalities are at one end of the spectrum and myocardial infarction is at the other. Minor metabolic defects slowly build up into major defects, thereby producing a spectrum of many different diseases. Diabetes shares a common etiology with hypertension, and diabetes and hypertension share a common etiology with heart disease and hypercholesterolaemia.
This means that somehow all these diseases are not really separate, but linked. It is the personal predisposition, the predisposed system, that manifests certain weaknesses earliest. One system can manifest diabetes, hypertension or heart trouble. It is the permutation and combination of variations in the personal predisposition, and in the presence of other etiological and structural factors, that lead to the manifestation of the predominant symptoms of a disease. Very commonly, in medical practice, we see diabetics with hypertension, and many also have heart problems sooner or later. These three conditions are commonly linked. Therefore, it is correct to call it a syndrome disease is really a syndrome.
Now, with documented proof that diseases are interrelated, scientists have reason to believe the postulates of yogis. There is a working hypothesis that stress leads to generalized disturbances in the metabolic and endocrinal secretions, where each and every cell of the body becomes diseased, whether the manifest symptoms are hypertension, diabetes, heart attack or stroke. If yogis are correct in their hypotheses, then the solutions they offer must have a definite preventive, promotive and curative value.
Yoga practices produce balance, harmony and integration in the physical and mental processes. The definition of asana, even in the traditional texts, is Sthiram sukham asanam. The word sthiram means homeostasis, balance, sukham means pleasure, and asanam is the physical posture. So, asana is a physical posture that produces homeostasis in the system, restores the endocrinal balance, balances the inhibitor and stimulator circuits and secretions, creates a sympathetic and parasympathetic balance, creates agonist and antagonist balance, and balances the entire system.
The physical postures are not only capable of producing a state of homeostasis in the body. Sukham relates to the state of mind, so asana also lead to a relaxed state of mind. Take the example of a tension headache. When there is tension, the muscles go into spasm, tending to produce a headache. On the other hand, by relaxing the muscles, the tension is relieved along with the headache. Asana is not heavy exercise. The muscles contain stretch receptors. The stretching movements of asanas send relaxing impulses to the brain, which produce a relaxed state of mind. This happens via the kinesthetic proprioceptor impulses, reaching the lower brain centres. That is how asana produces its effects.
We are all aware of how excitement of any kind, whether physical or emotional, leads to a quickening of the breathing rate. If we can slow down the breath, then we can move the cycle back and slow down the turbulent activities of the brain, thereby calming the mind. In many pranayamas the nostrils are used in a particular way during deep breathing exercises. The impulses from the nostrils travel into the hypothalamus, producing balanced functioning of the hypothalamus and the endocrinal, metabolic, sympathetic and parasympathetic activities of the brain. So pranayama works on the stress responsiveness of the limbic-hypothalamic system. There are many documented studies of this phenomenon.
It has been repeatedly demonstrated that yoga nidra and meditation produce a slow rhythm in the brain wave patterns. From a state of anxiety one moves to a relaxed state: from beta to alpha to delta. If brain wave activity is synchronized, then the brain is relaxed deep down to the reticular formation. The brain wave activity is calmed and these synchronized activities balance the stress-generating impulses from the limbic-hypothalamic complex. That is how yoga nidra acts as a preventive and curative measure in hypertension, peptic ulcer and all the psychosomatic disease syndromes.
In this way, there are many techniques and refinements to the practices of yoga. Each individual is given a different set of practices, depending on his/her condition, the nature of the disease, etc. The number, duration and sequence of the practices should be charted out by a medical expert and then the progress should be followed up. This is how the treatment of stress-related diseases can be linked with yoga.