How do you tell the difference between kidney stones and a kidney infection?

Different pain: Stones trying to pass in the ureter produce an intense pain that hits in waves. Though they may cause nausea and vomiting, they usually do not produce fever. The urinalysis may show blood but not full-field bacteria. A kidney infection, which may be caused by an obstruction stone, is marked with fever, pain, and a urine that is full of white blood cells and bacteria.