March 2008
How to read your urine
Fortunately, no one still practices the medieval art of assessing health by tasting the urine. But changes in your urine or
your urinary habits can provide warning signs of danger from disease or certain drugs—or they may be harmless changes caused
by food, supplements, or certain other drugs. This table can help you make that distinction. In general, consult your physician
promptly about a urinary change if you have not consumed any of the benign substances listed below, or if you have any of
the potentially harmful conditions or are taking any of the drugs listed. (Note that many of the drugs are available as generics.)
All but one of the potentially harmful medications affect the urine by impairing kidney function; the exception is warfarin, which can redden the urine by causing bleeding.
You may not have to contact your doctor quickly in two cases: You can usually treat dehydration simply by drinking more fluids if there are no other symptoms; and you can usually wait a day or two before calling your doctor about a suspected urinary-tract infection, unless you have severe symptoms, such as back pain or fever.
All but one of the potentially harmful medications affect the urine by impairing kidney function; the exception is warfarin, which can redden the urine by causing bleeding.
You may not have to contact your doctor quickly in two cases: You can usually treat dehydration simply by drinking more fluids if there are no other symptoms; and you can usually wait a day or two before calling your doctor about a suspected urinary-tract infection, unless you have severe symptoms, such as back pain or fever.
| Urinary signs or symptoms | Benign causes | Potentially harmful causes | ||
| Foods | Drugs and supplements | Drugs | Diseases and disorders | |
| Strong or foul-smelling urine | Asparagus | Vitamin B6 | None | Dehydration, urinary-tract infection, uncontrolled diabetes |
| Black or dark urine | Fava beans | Laxatives containing cascara(Nature’s Remedy), high-dose iron | Statin drugs such as atorvastatin (Lipitor) or simvastatin (Zocor) | Liver or kidney disease |
| Cloudy or murky urine | None | None | None | Urinary-tract infection |
| Green or blue urine | Food color additives | Artificial dyes in many drugs, amitriptyline, cimetidine (Tagamet) | None | Pseudomonas infection; “blue diaper syndrome,” an abnormality in the ability to digest tryptophan |
| Pink, red, or smoky brown urine | Beets, blackberries, other red foods | Laxatives containing cascara (see above) | Methyldopa, phenytoin (Dilantin), statins (see above), warfarin (Coumadin) | Kidney disease, rare genetic disorders, or bleeding caused by infection, prostate enlargement, kidney infection, kidney or bladder stone, or kidney, bladder, or prostate tumor |
| Yellow or orange urine | Carrots, rhubarb, beets, food color additives | Laxatives containing cascara (see above) or senna (Senokot); fluorescein (a dye used in certain eye exams); phenazopyridine (Pyridium); aloe; riboflavin; vitamins A, B12 | Rifampin (Rifadin), sulfa drugs (Gantrisin), warfarin (see above) | Dehydration caused by exercise, excessive heat, fever, or insufficient fluid intake |
| Decreased urination | None | Anticholinergics such as atropine (Sal-Tropine) and hyoscyamine (Levbid), contrast agents for imaging tests | Methotrexate (Trexall), sulfa drugs (Gantrisin) | Dehydration, acute or chronic kidney disease |
| Frequent urination (more than four to six times a day or waking more than once a night to urinate) | Excessive water consumption, caffeinated or alcoholic beverages | Diuretics such as furosemide (Lasix), hydrochlorothiazide (HydroDIURIL, Microzide); contrast agents for imaging tests | Lithium (Eskalith), phenytoin (Dilantin), tetracyclines (Declomycin) | Urinary-tract infection, enlarged or infected prostate, uncontrolled diabetes, sickle-cell anemia, heart or kidney failure |
| Hesitant urination (difficult to start) | None | Anticholinergics (see above), various cold medicines such as chlorpheniramine (Chlor-Trimeton), diphenhydramine (Benadryl Allergy); tricyclic antidepressants such as amitriptyline | None | Enlarged or infected prostate gland, urinary-tract infection, urethral stricture |
| Painful or burning urination | None | Cold medicines (see above) | None | Urinary-tract infection, vaginal or vulval irritation, sexually transmitted diseases |
