If your doctor is concerned that you have a kidney infection, he or she will ask you about other medical problems, any past infections and your recent symptoms. He or she will check your vital signs (temperature, heart rate, blood pressure), and will press on your abdomen and flanks to see if there is tenderness near the kidney. In women, the symptoms of pyelonephritis may be similar to those of certain sexually transmitted diseases, so your doctor may recommend that you have a pelvic examination.
To diagnose pyelonephritis, your doctor will order urine tests to look for white cells in the urine and for culture to determine the type of bacteria causing the infection. Usually your doctor will also order blood tests. Like the urine, the blood is sent for culture. People with pyelonephritis may have bacteria in their blood as well as their urine. Antibiotics are started prior to the culture results and will be adjusted once the bacterial species is identified in 24 to 48 hours.