Hundreds of oncological studies proved that growth of malignant tumors primarily depends on tissue hypoxia, but oxygenation of the human body is easier to measure: after your usual exhalation, pinch the nose and hold the breath, but only until the first stress. This stress-free and easy test accurately reflect body oxygenation.

For most people breath holding time is shortest during early morning hours. This usually happens between 4 and 7 am, when, according to epidemiological studies, severely sick patients with various chronic diseases are most likely to die.

Practical observations of MDs and family physicians practicing the Buteyko self-oxygenation breathing method revealed that tumors do not grow when body oxygenation is more than 20 seconds. However, when it is less than 20 seconds, due to reversal of the Krebb cycle (or citric acid cycle), anaerobic cellular metabolism develops, lactic acid concentration increases, and tumors can grow.

When oxygenation of the body is less than 10 seconds, the immune system offers little or no resistance to sepsis or bacteraemia and malignant cells can travel to distant tissues (metastasis).

Sleeping on one's back and mouth breathing produce strong negative effect on body oxygenation. Correspondingly, there are techniques to prevent sleeping on one's back and mouth breathing at night (taping the mouth at night using a surgical tape).

These ideas help to understand why it is so difficult for professional researchers to investigate cancer development. It happens due to the fact that oncology patients are usually examined during daytime, when their breathing is lighter and body oxygenation is much better than during early morning hours.

Elimination of tissue hypoxia and consistently high body oxygenation require gradual normalization of breathing and oxygenation based on the Buteyko self-oxygenation breathing method.