The causes for a blue or purple colored urine are limited.
Reasons for a bluish colored urine:
(1) biliverdiin
(2) indigo blue, indigo carmine or other dye
(3) methylene blue
(4) triamterene
In urine drug testing a blue dye is added to the toilet bowl water, which may rarely be submitted by the person being tested (perhaps someone who is color blind)
Reasons for a purplish urine:
(1) phenolphthalein (with urine acidic; red with alkaline urine)
To read more or access our algorithms and calculators, please log in or register.
