Does a simple urine test show a kidney infection or just a bladder one?

Shows both: It may miss a viral kidney infection in a transplant patient

Urine: Kidney infection is a serious organ infection and symptoms are impressive. High fever, pain and many systemic symptoms are present whereas a bladder infection may cause pain burning during passing urine. The urine test may be positive in both conditions maybe more impressive in kidney infection. Hope this answers your question.