Pyelonephritis can be divided into acute and chronic. Acute pyelonephritis is characterized by bladder irritation signs such as urinary frequency, urinary urgency and urinary pain, which may be accompanied by renal tenderness, lumbago, fever and chills. Chronic pyelonephritis is characterized by atypical systemic and localized urinary manifestations, sometimes only asymptomatic bacteriuria. 1. Acute pyelonephritis: urinary symptoms such as frequent urination, urgency, painful urination, difficulty in urination, etc., and systemic symptoms such as fever, chills, headache, generalized aches and pains, nausea, vomiting, etc. may be present. At the same time, there may be lumbar pain, renal area percussion pain and other typical local manifestations. 2. Chronic pyelonephritis is more complicated, and the systemic and local urinary manifestations may be atypical, and sometimes it only manifests as asymptomatic bacteriuria. There may be a history of acute pyelonephritis, followed by low-grade fever, intermittent urinary frequency, urinary discomfort, lumbar pain, nocturia, low specific gravity urine, etc. Although chronic pyelonephritis has the above manifestations, it is not easy to find the symptoms. Although pyelonephritis has the above mentioned manifestations, the diagnosis cannot be confirmed solely on the basis of the manifestations, but needs to be further confirmed by appropriate laboratory tests. For example, urine routine, blood routine, and urine culture if necessary. If pyelonephritis occurs, it is recommended to consult a doctor in time and treat it actively under the guidance of a physician.