In order to fully appreciate the powerful role of Ayurveda in restoring health, you need to understand how it helps you handle stress, which is at the root of many ailments big and small. Dr. Hans Selye, the pioneering researcher who practically invented the concept of stress, defined it rather poetically: "Stress is anything from a passionate embrace to a boring game of chess." Of course it is also a sock to the jaw, a pink slip, a divorce, a ring in your teenage daughter's nose (or your own parents' not letting you have a nose ring). Stress can be a windowless office with an uncomfortable chair or the knowledge that our species is destroying the natural environment.

Stress, then, can be anything that comes knocking on your door, but it is not necessarily the Big Bad Wolf himself, threatening to blow your house down. Rather the Big Bad Wolf is within you; it is your reaction to any event you believe to be stressful. You can either digest the stressful feelings and convert them to useful energy that helps you grow and develop or you can have trouble digesting stress and create ama, which tires out and depletes the nervous system and overworks the immune system, which in turn leaves the door open to illness.

So what happens when we are under stress? When we perceive something to be stressful, an internal alarm goes off, triggering a cascade of physiological changes that was originally described by Selye as a fight-or-flight response. Adrenaline floods the bloodstream, the heart beats faster; digestion screeches to a halt, muscles tense up, blood pressure skyrockets, the brain and senses become hyperalert. This response is designed to enable to us to fight for our lives or to get us away from the danger as fast as possible. It worked well for our ancestors because their stressors were mainly of the saber-toothed tiger variety. Stresses were immediate and short-lived, and once the dangerous situation was over, the body was designed to return to normal.Today life is not so simple or clear-cut. Instead a saber-toothed tigers we're continually barraged by little day-to-day hassles job insecurity or frustration, exasperating children, traffic jams, lack of fulfillment-that are difficult to fight or escape from. Nor is the stress response so simple and clear-cut. I now know that the way a person responds to stressful situations depends in part on the way he or she has learned to cope. necessarily harmful.

Fear, anger, and so on-these are all good, natural human emotions under certain conditions. But if they are not resolved and metabolized by your agni (that is, "digested"), they become stressful. The more stress we perceive, and the less able we are to cope with it, the less we are able to recover from it, and the less we are able to deal with new stressors.Prolonged stress wreaks all sorts of havoc: It can contribute to fatigue, diabetes, hypertension, ulcers, loss of libido, and reduced resistance to disease. Emotional upset can throw women's periods off kilter, reduce fertility, and make menopause more difficult. Feeling stressed affects your ability to work, to think clearly, and to have satisfying social relationships. In animal experiments stress has accelerated aging and death, hastened the spread of cancer, and promoted heart attacks. In 1993 the U.S. Public Health Survey estimated that 70 to 80 percent of Americans who visit physicians suffer from a stress-related disorder.