The yogis had precise concepts that were ratified by their methods of treatment. For example, according to the Yoga Upanishad, there are ten vital principles that have specific functions in the body. A dyspepsia problem is, according to yoga, governed by vital principles known as apana and naga. The former regulates build-up of air in the gastro-intestinal tract and the latter governs the act of belching. Asanas like twisting poses, forward and back bends, regulate the vital principles in the abdominal organs. When the patient practises twisting poses, the problem of excessive wind formation and belching is controlled. This is due to the regulation of the mechanisms that govern the orderly functioning of the cells. Obviously, such situations have to be experienced and cannot be explained by theory.
Doctors are disinclined to accept drugs or surgery for their own chronic conditions knowing, as they do full well, the limitations of `symptomatic therapy'. They would much prefer a permanent solution. Like yoga. Typical examples are low back pain and essential hypertension, where the role of drugs is limited if yoga therapy is begun early.
In the case of blood pressure, only the elevated blood pressure is neutralised by drugs. The exact cause for the malfunction is untouched. Of course, the general advice to `reduce stress' is given. To reduce stress is easier said than done. Yoga boosts and strengthens the enormous inner defensive energy to control the offensive forces and offers an alternate method that is non-invasive, and non-drugging.
Yoga uses postures to correct inner malfunction according to natural principles. It is important to minimise the use of drugs whenever possible and employ natural methods that, in the long run, preserve the sensitivity of the body. Such a body will be more responsive to treatment than one that has been constantly exposed to drugs. Take the case of recurrent sore throats in children. Often, repeated doses of antibiotics are prescribed. Yet, the infection recurs. Sarvangasana and half halasana are very useful in such cases.
Patanjali has said that the disease process can be dormant, attenuated, interrupted, or fully active. Yoga treats diseases using the process in reverse - the active disease is first rendered interrupted, then attenuated, and then made to disappear after passing through a stage of being dormant. The yogic approach is step by step, and is never in a hurry. It works along the principles of evolution of a disease.