The Russian Breathing Method

Konstantin Pavlovich Buteyko studied medicine in the 1940s at the First Medical Institute of Moscow. One of his practical assignments involved monitoring the breathing of terminally ill patients. After hundreds of hours spent observing breathing patterns, he was able to accuracy predict the time of death of each patient. Each patient's breathing increased as their condition deteriorated and as they approached death.
While at University Buteyko was diagnosed with malignant hypertension, a fatal form of blood pressure which gave him a life expectancy of only 12 months. He began to wonder whether the cause of his condition might be his deep breathing. One night he checked this by reducing his breathing, and within minutes his pain ceased. To confirm his discovery, he took five deep breaths and the pain returned. He again reversed his deep breathing and the pain disappeared. Buteyko then measured the breathing patterns of sufferers of asthma, angina and other diseases, discovering that they too were hyperventilating. Once again by correcting these patients' breathing patterns Buteyko was able to stop their attacks immediately.
After further research Buteyko laid down the theoretical foundation for this idea - hyperventilation causes a depletion of carbon dioxide; low levels of carbon dioxide in the organism cause blood vessels to spasm and also cause oxygen starvation of the tissues. This results in a whole range of "defense mechanisms" that have been previously misunderstood and labeled as diseases.