Two cases illustrating the difficult differential diagnosis of left-si
ded pain in the coincidence of nephropathy and aortic aneurysm are des
cribed. In both cases an aortic aneurysm was discovered, although the
aneurysm caused the pain in the side in only one case. In particular,
older men with recently occurring side or back pain must be examined w
ith regard to aortic aneurysm. As the classic symptoms of a ruptured a
neurysm are frequently disguised, aneurysm must always be considered a
s a cause of left-sided pain.