Pyelonephritis is an infectious inflammation. Pyelonephritis is an infectious inflammation due to pathogenic microorganisms such as bacteria, viruses, fungi, mycoplasma, chlamydia, etc., and pathologically it is mainly characterized by exudative inflammation. The most common pathogenic microorganisms in pyelonephritis are gram-negative bacilli, in addition to gram-positive cocci, mycoplasma, chlamydia, viruses, fungi, and so on. Patients may have bladder irritation symptoms such as urinary frequency, urgency and pain, and most of the patients are accompanied by systemic toxicity manifestations such as fever, chills, nausea and vomiting, and some of the patients may have ureteral point pressure pain or renal area percussion pain. Pyelonephritis patients need to complete the urine culture examination as soon as possible, according to the results of the culture to choose the appropriate anti-infective drugs for treatment, do not self-medication.