Causes Of Urine Color Changes
Color | Cause |
|---|---|
Red, orange, or brown | Bilirubin Hemoglobinuria Medications (eg, cascara sagrada, phenytoin, levodopa, methyldopa, phenazopyridine, phenindione, phenolphthalein, phenothiazines, rifampin, senna)Medications (eg, cascara sagrada, phenytoin, levodopa, methyldopa, phenazopyridine, phenindione, phenolphthalein, phenothiazines, rifampin, senna) Foods (eg, beets) Free myoglobin Porphyrins Red blood cells |
Cloudy white | Infection (pyuria) Lymph (chyluria) due to filariasis or to obstructed retroperitoneal lymphatics Precipitated phosphate crystals |
Green | Medications (eg, amitriptyline, methylene blue, propofol)Medications (eg, amitriptyline, methylene blue, propofol) Pseudomonas infection |
Purple (rare) | Gram-negative bacteria in urinary catheters* |
Dark brown or black | Melanoma† |
* Rarely, urine in collection bags of catheterized, bedbound patients turns purple (purple urine bag syndrome) when urinary gram-negative bacteria metabolize a tryptophan metabolite (indican) in alkaline urine into indigo; this reaction is clinically insignificant. | |
† Caused by oxidation of excessive homogentisic acid or melanogen when urine is exposed to air for several hours. | |