You are working at an urgent care clinic when a patient is brought in by several of his friends. He is conscious but seems very confused. At first, the friends say they're worried because he had too much to drink, but then they admit that he was using drugs also. The patient's hands are shaking, and when he wipes his nose with a tissue, you can see blood on the tissue. Which of the following conditions would the physician likely be most concerned about?

- Pyelonephritis
- Glomerulonephritis
- Polycystic kidney disease
- Acute renal failure
- Renal calculium