I was talking to my Indian buddy, and stress can be a factor in our daily lives and health. He was recommending two breathing exercises that can have profound impact on our lives and longevity. One was anulom vilom, and the other was kapal bhati, you can look these up on the net to find exactly how to do them. He was saying that the old yogis of India whom practiced these daily were able to live upto 150 years old. They are supposed to be very beneficial to the body according to him. Try and see if they help you Best of luck.