That the pathogenesis of orthostatic albuminuria is poorly understood is attested by recent reviews.1 The name orthostatic albuminuria is derived from a clinical symptom—the presence of an increased amount of protein in the urine while the subject is erect and its fall to a normal level (clinical absence) when he is supine. The object of this paper is to indicate the importance of determining the anatomic basis for this symptom by means of roentgenograms made after the injection of diodrast. The experience of my colleagues and myself in the first five cases in which this method was applied seems to indicate that orthostatic albuminuria arises from diverse anatomic anomalies and cannot be regarded as a distinct entity.
Two general theories may be considered seriously, the circulatory and the mechanical theory. The circulatory theory explains the anomaly on the following bases: First (a) in orthostatic albuminuria the amount of protein