“…In some patients hypertension develops after an attack of previously unexplained upper abdominal or loin pain (Poutasse 1956 10 ; Adams and Newman 1958) 11 and this sequence should suggest the possibility of thrombosis in the renal artery. The thrombosis may occur upon an atheromatous plaque, or in the walls of an aneurysm, or it may follow embolism of the renal artery (Prinzmetal et al 1942 12 ; Bourne 1954) 13 . It may be accompanied by fever and leucocytosis and thus be mistakenly diagnosed as acute pyelonephritis.…”