Fever and back pain. Kidney infection or pyelonephritis is usually bacterial in nature and related to a urinary tract infection. Symptoms include fever, abdominal pain, painful urination, and costovertebral tenderness (pain in your back between the 12th rib and spine). Your doctor can diagnose pyelonephritis with simple urine tests and physical exam.
Pain, fever, blood. Flank pain or pain deep to ribs at back, upper abdominal pain, fever with chills, blood in urine, generally feeling rotten, occasionally vomiting. Also symtoms of bladder infection - burning senastion with urination, urgency +/or frequency of urination. Seroius condition which should be treated asap.