Until recently, hypertension was considered entirely the result of arterial and renal disease. Although the mechanism whereby such disease caused hypertension was unknown, the almost constant association of the symptom and such lesions seemed to justify such a conclusion. This was in accord with the still dominant tradition of the continental school; namely, that an abnormal function must necessarily be the result of a morphologic tissue change. It is becoming increasingly apparent, however, that an association of a lesion with a functional change does not always necessarily imply that this change is the result of the lesion. The lesion may represent an end-result of influences in which the functional change is the main or an important factor.
Correlation of pathologic evidence and clinical data furthermore revealed striking discrepancies: 1. Hypertension was present although at postmortem there was little evidence of arterial or vascular disease. Such cases are by no means