Which infection is a specific type of urinary tract infection that begins in the urethra or bladder and travels up to the kidneys?

• A. IUP
• B. Pyelonephritis
• C. Nephrolithiasis
• D. PID

Answer: (B)

The key idea here is ascending infection within the urinary tract. Pyelonephritis is an infection of the kidney that results when bacteria from the urethra or bladder travel up the ureters to infect the renal pelvis and kidney tissue. This makes it an upper-tract infection, distinct from infections that stay in the bladder (cystitis). Because the bacteria reach the kidney, patients often develop fever and flank pain with tenderness over the costovertebral angle, and may also have nausea or vomiting in addition to urinary symptoms. The other conditions listed represent different problems and do not describe an infection that ascends to the kidneys.