Alternative name: Discolouration of urine
Definition: The usual colour of urine is straw-yellow. Abnormally coloured urine may be cloudy, dark or blood-coloured.
Abnormal urine colour may be caused by infection, disease, medicines or food you eat.
Cloudy or milky urine is a sign of a urinary tract infection, which may also cause a bad smell. Milky urine may also be caused by bacteria, crystals, fat, white or red blood cells or mucus in the urine.
Pink, red or lighter brown urine can be caused by:
- Beets, blackberries or certain food colorings
- Hemolytic anemia
- Injury to the kidneys or urinary tract
- Urinary tract disorders that cause bleeding
- Blood from vaginal bleeding
- Tumour in the bladder or kidneys
Dark yellow or orange urine can be caused by:
- B complex vitamins or carotene
- Medicines such as phenazopyridine (used to treat urinary tract infections), rifampin and warfarin
- Recent laxative use
Green or blue urine is due to:
- Artificial colours in foods or drugs
- Medicines, including methylene blue
- Urinary tract infections
When to Contact a Medical Professional
See your health care provider if you have:
- Abnormal urine colour that cannot be explained and does not go away
- Blood in your urine, even once
- Clear, dark-brown urine
- Pink, red or smoky-brown urine that is not due to a food or drug
What to Expect at Your Office Visit
The provider will perform a physical exam. This may include a rectal or pelvic exam. The provider will ask you questions about your symptoms such as:
- When did you first notice a change in urine colour and how long have you had the problem?
- What colour is your urine and does the color change during the day? Do you see blood in the urine?
- Are there things that make the problem worse?
- What types of foods have you been eating and what medicines do you take?
- Have you had urinary or kidney problems in the past?
- Are you having any other symptoms (such as pain, fever or increase in thirst)?
Tests that may be done include:
- Blood tests, including liver function tests
- Ultrasound of kidneys and bladder
- Urine culture for infection
Gerber GS, Brendler CB. Evaluation of the urologic patient: history, physical examination, and urinalysis. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology. 11th ed. Philadelphia, PA: Elsevier; 2016:chap 1.
Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 114.