Natural history of chronic asthma and its long-term effects on pulmonary function.

Although asthma is a disease that has intrigued physicians since antiquity, its natural history has been incompletely determined. It has long been held that the presence of asthma, per se, does not carry with it any long-term deterioration in lung function, but recently this view has been challenged, and it has become fashionable to define asthma as being only partially reversible. At present, there are limited data to support such a view. All of the available information indicates that the vast majority of patients do not experience the development of a progressive decline in pulmonary mechanics or appear to be at risk for a diminution in life expectancy.