“…Dyspnoea and X-ray signs of advanced emphysema are even more frequent with past infections. Past lung infections are obviously related, at least in men of this age group, to decreased functional pulmonary reserve, eventually to pulmonary insufficiency (29). Obviously, functional pulmonary reserve may be reduced as a result of manifest pulmonary infections, or on the other hand it may be related to chronic bronchial mucus hypersecretion, which has a close correlation with cigarette smoking.…”