In 1939, Irwin Page performed an experiment in a dog model in which one kidney was wrapped in cellophane. The resultant external compression on the kidney resulted in elevated renin-angiotensin-aldosterone levels and severe hypertension. Over time, a loss of renal function occurs due to some degree of renal ischemia and constrictive perinephritis. Because there are high levels of circulating aldosterone, renal K-wasting and hypokalemia can also be present.
Now, "Page Kidney" refers to any condition in which external compression of the kidney leads to activation of the renin-angiotensin-aldosterone system resulting in hypertension. The most common cause of a Page kidney is a subcapsular hematoma, which can result from blunt trauma or iatrogenesis, such as a renal biopsy or ESWL for kidney stones. Rarely, large cysts or tumors can also cause Page kidney.