The infection may be bloodborne, ascending from the bladder or an extension from an adjacent focus. Obstruction of the flow of urine, as caused by calculi, hypertrophy of the prostate and tumors, often favors infection.
The symptoms are high swinging fever with rigors, as well as pain and tenderness in the loin. This condition is usually associated with irritation of the bladder evidenced by urgency and frequency of urination. The urine contains pus, cellular casts, and often, red blood cells. Culture of the urine usually reveals the responsible microorganisms, the most common of which are colon bacilli, streptococci, staphylococci, and Proteus vulgaris. IVP may be of diagnostic value. Treatment consists of antimicrobial medication and appropriate measures against the underlying cause.