Results After pneumomediastinum(PM),as compared with the baseline measurements,the venacaval pressure raised and the cardiac output decreased significantly.
These two are different in that chronic bronchitis is defined by clinical features, like a productive cough, whereas emphysema is defined by structural changes —specifically enlargement of the air spaces.
The things that are caused by the environment like smoking cigarettes causing COPD or emphysema or pulmonary fibrosis, which is scarring in the lungs, those things don't heal.