The Buteyko method is based on the concept that "hidden" or undiagnosed hyperventilation is the underlying cause of numerous medical conditions, including asthma. It is known that hyperventilation can lead to low carbon dioxide levels in the blood (or hypocapnea), which can subsequently lead to disturbances of the acid-base balance in the blood and lower tissue oxygen levels. Advocates of this method believe that the effects of "chronic" hyperventilation would have even wider effects than is commonly accepted. These effects include widespread spasms of the muscle in the airways (bronchospasm), disturbance of cell energy production via the Krebs cycle, as well as disturbance of numerous vital homeostatic chemical reactions in the body. The Buteyko method is a purported method of "retraining" the body's breathing pattern to correct for the presumed "chronic" hyperventilation and hypocapnia, and thereby treat or cure the body of these medical problems.