The difference between urinary tract infection and pyelonephritis: 1. Urinary tract infection is a larger category that includes infections in all parts of the urinary tract, while pyelonephritis is a specific infection, which means that only infections that occur in the renal pelvis are called pyelonephritis. The infection of the ureter, bladder, and urethra can be called a urinary tract infection, but not pyelonephritis. 2. Pyelonephritis is an infection of the upper urinary tract, which is an infection that occurs above the bladder and often causes an increase in pressure in the renal pelvis and an acute inflammatory response in the mucosa of the pelvis, with back pain and fever as the main manifestation, supplemented by symptoms of urinary tract irritation. The urinary tract infection can be accompanied by back pain, fever, more serious urinary tract irritation and even increased urethral secretion, while pyelonephritis does not show increased urethral secretion. 3. The treatment can also be done by infusion, etc.