Pyelonephritis is a clinical type of urinary tract infection, which refers to the inflammatory disease caused by the growth and reproduction of various pathogens in the renal pelvis. Pyelonephritis is usually divided into acute pyelonephritis and chronic pyelonephritis. Acute pyelonephritis is primarily characterized by frequent urination, urgency, painful urination, chills, fever, back pain, overall muscle soreness, and tenderness or percussion pain in one or both kidney areas. Chronic pyelonephritis, on the other hand, shows varying degrees of bilateral renal damage, reduced kidney size, rough surfaces, renal papillary scars, renal tubular atrophy, and chronic inflammation signs such as lymphocyte infiltration in the renal interstitium. Chronic pyelonephritis typically presents with low-grade fever, weight loss, backache, and anemia. Therefore, sufficient attention should be given to pyelonephritis, as chronic pyelonephritis can lead to uremia in patients.