A 23-year-old man presented to the emergency department with thigh and flank pain. His medical history was unremarkable. Serum test results included the following: aspartate aminotransferase, 4007 U/L (reference interval, 11–47 U/L); alanine aminotransferase, 715 U/L (reference interval, 7–53 U/L); alkaline phosphatase, 67 U/L (reference interval, 38–126 U/L); lactate dehydrogenase, 6150 U/L (reference interval, 100–250 U/L); creatinine, 1.6 mg/dL (141 μmol/L) [reference interval, 0.7–1.3 mg/dL (62–115 μmol/L)]. A urine sample (Fig. 1) was also collected at the time of presentation.

Fig. 1.


  1. What conditions might cause urine to have this appearance?
  2. What laboratory tests might be useful for patients with dark brown urine?

Read the article here for the answers.