According to Yoga, stress is an imbalance at the mental, physical, or emotional level. It is not the cause of our ills, but the cause is one's inability to cope with a changing condition. Yoga balances, harmonizes, and brings integration between physical and mental health. Yogic methods of stress management include: maintaining the physical body through the practice of Asana, awakening the vital energy through Pranayama, relaxation through Yoga-nidra, and through food - the source of Prana.
The most advanced techniques, in Yoga, are based around training the mind. Patanjali mentions eight limbs in the Yoga Sutras. All eight limbs will train the mind, but the last four limbs are especially for balancing and training the mind.