Obesity

It might be helpful for asthmatics to take a look at seriously overweight people. You can see that their bodies have grown but will not be able to see that their lungs have not. If lungs are too small for the body then the person concerned will suffer from a lack of oxygen (hypoxia) and this will lead to excessive weight gain, particularly at high elevations above sea level or during sleep. If lungs and the trachea are too small or narrow then insufficient air in accommodated and this in turn can lead to hyperventilation when the heart needs more oxygen.