Table 2.
Causes of discolored urine.
| Red-colored urine | Hematuria (RBCs) |
| Myoglobinuria (myoglobin and rhabdomyolysis) | |
| Hemoglobinuria (free hemoglobin) | |
| Porphyria (porphyrin) | |
| Urate crystals | |
| Foods (food coloring, beets, and blackberries) | |
| Drugs (phenolphthalein, chloroquine, phenazopyridine, iron sorbitol, desferrioxamine) | |
|
| |
| Dark yellow- or orange-colored urine | Concentrated urine |
| Drugs (rifampin and pyridium) | |
|
| |
| Dark brown- or black-colored urine | Bile pigments |
| Methemoglobinemia (methemoglobin) | |
| Melanin | |
| Alkaptonuria (homogentisic acid) | |