red urine
Last reviewed 01/2018
Causes include:
- haematuria
- foods - such as beetroot
- drugs:
- phenolphthalein
- rifampicin
- disease processes:
- myoglobinuria
- haemoglobinuria
- porphyria
Notes:
- urine may be apparently red as result of blood from other sources - menstrual blood or perianal blood
- red in acid urine only - beetroot, blackberries
- red in alkaline urine only - anthraquinone laxatives, rhubarb, santonin; eosin produces green fluorescence
- porphyrins - urine darkens on standing
- urine turns red on contact with hypochlorite bleach (toilet bowl cleaner) - aminosalicylic acid