A: Yes. Dr. Buteyko discovered that chronic hyperventilation can be very dangerous or even lethal. In order to protect itself, the body creates various defense mechanisms to reduce hyperventilation. Coughing, wheezing, suffocation attacks, excessive mucus, and stuffy nose are just a few of these mechanisms. The purpose of each of these ‘symptoms’ is to reduce hyperventilation, thereby protecting the body from even greater harm. When a person reduces his or her hyperventilation voluntarily, the body no longer relies on these symptoms as a means to prevent hyperventilation. Many people greatly reduce symptoms within the first few weeks of doing breathing exercises. Many people lose their symptoms completely. To understand the scientific theory of this breathing method please read an explanation written by Dr. Buteyko.