Sleep apnea, in its simplest form, is a message from the brain to the respiratory system warning that too much CO2 is being lost. As soon as CO2 levels drop, the blood becomes more alkaline and, as it approaches the threshold of respiratory alkalosis, the brain attempts to redress the situation by stopping breathing. In this apnea pause, the CO2 rises to an acceptable level allowing the patient to breathe once more. However, if the next breath is too big, as it is after an apnea pause, too much CO2 is exhaled and the whole process is repeated.

By retraining the breathing response and by reducing the volume of air per breath, and the number of breaths per minute, many apnea sufferers have found relief without having to resort to a CPAP machine.