The usual color of urine is straw-yellow. Abnormally colored urine may be cloudy, dark, or blood-colored.
Discoloration of urine
Abnormal urine color 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.
Gerber GS, Brendler CB. Evaluation of the urologic patient: History, physical examination, and the urinalysis In: Wein AJ, ed. Campbell-Walsh Urology. 10th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 3.
Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 116.
Louis S. Liou, MD, PhD, Chief of Urology, Cambridge Health Alliance, Visiting Assistant Professor of Surgery, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.