title: Smoking and the development of progressive airflow obstruction.
abstract: An overall relation between cigarette smoking and the development of progressive airflow obstruction is established but only a minority of smokers ever develop severe airway narrowing; with the striking but rare exception of homozygous alpha 1-antitrypsin deficiency, the causes of this variation in susceptibility between smokers are uncertain. Possible associated risk factors may be classified under three broad headings--exogenous irritants, broncho-pulmonary infections and endogenous or 'host' factors--and will be briefly reviewed in this paper. But first the natural history of progressive airflow obstruction must be considered because this determines how potential risk factors can be assessed.
mesh_terms: D000367:Age Factors; D000393:Air Pollutants / Q000009:adverse effects; D005541:Forced Expiratory Volume; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D010641:Phenotype; D011379:Prognosis; D012141:Respiratory Tract Infections / Q000150:complications; D012907:Smoking; D013183:Sputum / Q000378:metabolism; D019896:alpha 1-Antitrypsin Deficiency
chemical_list: D000393:Air Pollutants