(See Overview of Urinary Tract Symptoms Overview of Urinary Tract Symptoms Kidney and urinary tract disorders can involve one or both kidneys, one or both ureters, the bladder, or the urethra, and in men, the prostate, one or both testes, or the epididymis. Problems... read more .)
Normally, dilute urine is nearly colorless. Concentrated urine is deep yellow. Colors other than yellow are abnormal.
Doctors usually can identify the cause of an abnormal color by examining the urine under a microscope or by doing chemical tests.
Drugs can produce a variety of colors: brown, black, blue, green, orange, or red.
Treatment is unnecessary except if needed to treat the underlying disorder.
Brown urine may be caused by broken-down hemoglobin (the protein that carries oxygen in red blood cells). Broken-down hemoglobin can leak into the urine when bleeding occurs in the kidney, ureter, or bladder, or it can be excreted into the urine as the result of certain disorders that damage or destroy red blood cells (hemolytic anemia Autoimmune Hemolytic Anemia Autoimmune hemolytic anemia is a group of disorders characterized by a malfunction of the immune system, resulting in the production of autoantibodies that attack red blood cells as if they... read more ). Brown urine also may be caused by muscle protein (myoglobin) that is excreted into the urine after severe muscle injury.
Urine may be black because of pigments produced by melanoma.
Red urine may be caused by blood in the urine Blood in Urine Blood in the urine (hematuria) can make urine appear pink, red, or brown, depending on the amount of blood, how long it has been in the urine, and how acidic the urine is. An amount of blood... read more but it may also be due to food pigments (for example, from beets), artificial food coloring, and rarely by porphyria Porphyrias .
Cloudy urine suggests the presence of excess white blood cells due to a urinary tract infection Overview of Urinary Tract Infections (UTIs) In healthy people, urine in the bladder is sterile—no bacteria or other infectious organisms are present. The tube that carries urine from the bladder out of the body (urethra) contains no bacteria... read more , the presence of crystals of salts from uric acid or from phosphoric acid, or the presence of a vaginal discharge.
The odor of urine can vary and does not usually indicate a disorder except in people who have certain rare metabolic disorders. For example, concentrated urine can have a strong smell of ammonia. Also, a urinary tract infection can cause foul-smelling urine.