Urine is made up of excess water and waste products that have been filtered from your blood by your kidneys. Its yellow color comes from urochrome, a pigment that results from the breakdown of hemoglobin, the oxygen-carrying protein in red blood cells.
Discolored urine is often caused by medications, certain foods or food dyes. For instance, the dyes used in some sugary cereals can show up in kids' urine. In some cases, though, changes in urine color may be caused by certain health problems.
Here's a look at possible causes for abnormal urine color:
Red or pink urine
Despite its alarming appearance, red urine isn't necessarily serious. Causes include:
Blood. The presence of red blood cells is the main reason urine turns red. Usually, bleeding isn't severe and occurs without other signs or symptoms. Factors that can cause urinary blood, known medically as hematuria, range from strenuous exercise, urinary tract infections and an enlarged prostate to kidney or bladder stones, kidney disease, and, occasionally, kidney cancer or bladder cancer.
Foods. Beets, blackberries and mom's rhubarb pie can turn urine red or pink.
Medications. Certain laxatives — Ex-lax is an example — can cause red urine. Prescription drugs that have the same effect include antipsychotics such as chlorpromazine and thioridazine and the anesthetic propofol (Diprivan).
Toxins. Chronic lead or mercury poisoning can cause urine to turn red. This may be the result of high levels of excreted porphyrins, the same pigments that discolor the urine of people who have porphyria.
Orange urine is hard to miss. Blame it on:
Foods and supplements. Leading food culprits include vitamin C and carrots and carrot juice. Large amounts of carotene, the orange pigment in carrots, winter squash and other vegetables, can also discolor the palms of your hands and soles of your feet.
Medications. Medications that can turn urine orange include the antibiotic rifampin (Rifadin); the blood thinner warfarin (Coumadin); phenazopyridine (Pyridium), which treats urinary tract discomfort; some laxatives and certain chemotherapy drugs.
Dehydration. Drinking too few fluids can concentrate urochrome, making urine much deeper in color.
Blue or green urine
Blue or green urine can result from:
Foods. Asparagus may give urine a greenish tinge as well as a characteristic odor.
Medications. A number of medications produce blue urine, including amitriptyline, indomethacin (Indocin), cimetidine (Tagamet), the anti-nausea drug Phenergan and several multivitamins. A dye used in several medications that treat urinary pain (Urised, others) can turn urine blue.
Medical conditions. Familial hypercalcemia, a rare inherited disorder that causes high levels of calcium, is sometimes called blue diaper syndrome because children with the disorder have blue urine.
Dark brown or tea-colored urine
Food. Eating large amounts of fava beans, rhubarb or aloe can cause dark brown urine.
Medications. A number of drugs can darken urine, including the antimalarial drugs chloroquine and primaquine; the antibiotic metronidazole; nitrofurantoin, which treats urinary tract infections; laxatives containing cascara or senna; and methocarbamol, a muscle relaxant.
Medical conditions. Some liver disorders, especially hepatitis and cirrhosis, and the rare hereditary disease tyrosinemia can turn urine dark brown. So can acute glomerulonephritis, a kidney disease that interferes with the kidney's ability to remove excess fluid and waste.
Cloudy or murky urine
Urinary tract infections and kidney stones can cause urine to appear cloudy or murky.