Health is Wealth; it is true now and then. Sound health includes physical, mental and spiritual. A healthy man can live with happiness; he can perform his duty perfectly. The medical scientists conducting research and discovering different medicines for cure of diseases, but these medicines could not success the cure diseases and maintain of the health. Therefore, the modern man turns back to traditional practices, like Yoga and Ayurveda. The asthanga yoga propounded by Sage Patanjali, it is origins of the all the types of yoga’s. Today, in the 21st century, a spiritual heritage is being reclaimed of which Yoga is very much a part. While Yoga’s central theme remains the highest goal of the spiritual path, yogic practices give direct and tangible benefits to everyone regardless of their spiritual aims. Thus, in this study discussed the body structure, function of organs, the main principles of asthanga yoga, various research studies on yoga and its effect in the cure of the diseases, particularly asanas (postures) and pranayama (proper breathing). The yoga practice very much benefit to the healthy man compare with the ill health. Prevention is the better than cure.