Relatively little advance has been made in the understanding of the etiology of pulmonary emphysema in the past 150 years. The present concepts differ little from those of Laennec. The purpose of this article is to review the hypotheses regarding the etiology of emphysema and to attempt to determine which of these might lead to productive experimentation. There is often a lack of appreciation of the need for and usefulness of hypotheses in guiding experimentation. Without a meaningful hypothesis, gathering of data becomes an end in itself and the very weight of the facts accumulated may confuse rather than clarify the issue. It is also not generally appreciated that a hypothesis may eventually prove to be invalid and yet lead to useful and important experiments.
Definition of Pulmonary Emphysema
Before considering the hypotheses regarding the etiology of emphysema it is necessary to define the disease. The definition of emphysema has
EBERT RV, PIERCE JA. Pathogenesis of Pulmonary Emphysema. Arch Intern Med. 1963;111(1):34–43. doi:10.1001/archinte.1963.03620250038006