Yoga is an integral part of Ayurvedic treatment principle. Ayurveda considers health as the state of Clear Soul, Sense Organs and Mind. And to attain this clarity and calmness you need Yoga. Charaka Samhitha, the oldest text of Ayurveda calls Yoga – the reliever of all diseases affecting body and mind.
Yoga involves an 8 fold program. Following a healthy and ordered lifestyle called YAMA and NIYAMA. Then the most famous aspect of Yoga- Various body postures called as Asana used for stabilizing the body as a preparation for meditation. After this is Pranayama- or breathing exercises, which helps to concentrate the mind on your breath. Then comes Prathyahara - a process of concentrating and observing mind without attaching to the sense organs. Dharana the next step is concentrating mind to a point. The next step is Dhyana or meditation in a fully relaxed stage and finally Samadhi or enlightenment.
Effects on the body
A number of clinical studies conducted in India on healthy individuals doing Yoga, essentially comprising Asanas and Pranayama, have shown that yoga practice improves body weight, stabilizes blood pressure, increase insulin levels, reduce  triglycerides, blood sugar levels and pulse rate. Regular practice of Yoga has been found to increase the vital capacity of lungs, maximum voluntary ventilation, breath holding time and maximal inspiratory and expiratory pressures. Studies in healthy young subjects have found that performing Asanas increase the sensitivity of the β cells of the pancreas to the glucose signal create a glucose balance in the body and may be helpful in preventing Diabetes Mellitus. Yoga is universally popular as a form of physical fitness and exercise, and has been found to improve strength and flexibility.
In Diseases
Various schools of Yoga uses Yogic techniques which primarily concentrate on Body Postures and Breath control as a means to relaxation and as a treatment for ailments. According to on an analysis of multiple studies, it was suggested that yoga training involving breathing exercises that lasts from 12 weeks to 9 months may improve lung function and functional exercise capacity in patients with Chronic Obstructive Pulmonary Disease when compared with conventional therapy. Yoga therapy has been also found to positively improve biochemical parameters in Asthmatic subjects. It has also been found effective in smoking cessation in case of chronic smokers.
Practicing Yoga has been found to be beneficial in improving balance, pain and quality of life and improved cognition in older people who are frail and dependent with physical and cognitive limitations.
Stress is one of the greatest triggers of disease causation and worsening in the modern world. In a meta-analysis of 17 studies, it was found that 16 demonstrated positive changes in psychological or physiological outcomes related to anxiety and/or stress. In a controlled study of Yoga Therapy in patients with Migraine headaches, it was observed that it had beneficial effects on headache duration, disability, self-efficacy, and improved pain bearing capacity. A similar result was observed in patients with fibro myalgia, a musculo-skeletal psychosomatic disorder. There is strong evidence to suggest that Yoga therapy is very effective as a short-term and long-term remedy for chronic low back pain. Yoga therapy is now a scientifically proven effective treatment for OA knees.

There is also initial evidence to suggest that Yoga therapy is beneficial in improving Health Related Quality of Life and physical fitness in cancer patients. This is a very promising finding in a population where sedentary behavior and the associated co-morbidities are a growing concern.