You would be surprised by how much information can be gleaned from the urine that you produce each day (one to two quarts, on average). For example, the simple "dipstick" urine test that doctors often use to check for a urinary tract infection also can help them diagnose kidney disease, diabetes, cancer and other conditions. But there is more.
What you may not realize: If you know what to look for, you can tell a lot about your health just by being aware of the physical characteristics of your urine-such as color, smell and frequency. What to watch out for...
When you're healthy and drinking enough water, your urine should be mainly clear or straw-colored with just a hint of yellow. The yellow color comes from urochrome, a pigment produced by the breakdown of a protein in red blood cells.
Urine is naturally darker in the morning because you don't drink water while you sleep. If a color change persists, however, it could be a problem. For example...
Brown or dark brown. Pay attention if your urine is dark for more than a week.
What this usually means: Liver disease. The liver normally breaks down and excretes bilirubin, a pigment that's produced by the turnover of red blood cells. Patients with liver disease accumulate bilirubin. This initially will cause jaundice, a yellowing of the skin or the whites of the eyes. As more bilirubin accumulates, it can cause the urine to become brown. A combination of dark-colored urine and jaundice means that liver disease might be getting worse. See your doctor right away.
Dark-colored urine also can be a side effect of some antibiotics, laxatives and muscle relaxants. Eating large amounts of fava beans, rhubarb or aloe can cause brown urine as well. In some cases, dark-colored urine can signal kidney failure.
Red or pink. Urine that's tinged with red or pink could simply mean that you have been eating beets. (The medical term for beet-induced urine changes is beeturia). Or it could mean that you're urinating blood.
The amount of blood will affect the color. If the urine resembles cabernet wine, you're bleeding a lot... urine that's pinkish or just slightly red contains only traces of blood. A microscopic amount of blood won't be visible-it can be detected only with a laboratory test.
What this usually means: Blood in the urine is always a problem. Make an appointment to see your doctor. If you see blood and it also hurts when you urinate, you could have an infection-in the urethra, bladder or kidney or even a malignancy in the bladder, for example. Bleeding without pain also can indicate these conditions.
Green. Though rare, a person's urine can turn a greenish color.
What this usually means: Green urine can appear when you've consumed a chemical dye-from food coloring, for example, or from taking medications such as amitriptyline, an antidepressant, or indomethacin (Indocin), a nonsteroidal anti-inflammatory drug. In some cases, urine with a greenish tint can signal a urinary tract infection with certain bacteria (such as pseudomonas) that affect the color. If your urine is greenish, increase fluid intake to see if it clears. If it doesn't in two days, see your doctor or a urologist.
If you're healthy, your urine should be highly diluted, consisting of about 95% water, with only small amounts of dissolved chemical compounds and metabolic by-products. It typically has no-or only a faint-odor.
Of course everyone is familiar with the effect that asparagus and some other foods, such as onions or fish, have on the smell of one's urine. This strong "rotten" smell is due to the chemical compounds in certain foods, particularly molecules that are not completely broken down by the body. The smell usually disappears within a day or so.
Some other less common urine smells include...
Ammonia-like. If your urine is concentrated, with a larger-than-normal amount of urea (a chemical compound in urine), you might smell an aroma that resembles ammonia. Or you might just notice that it has a stronger smell than usual.
What this usually means: Dehydration. The less water you drink, the higher the concentration of urea and other substances-and the stronger the smell. You can diagnose this yourself by drinking, say, one extra glass of water an hour for several hours to add water to your urine. The strong urine smell will probably disappear within a few hours. If it does not, see your doctor.
Foul-smelling. If your urine smells foul or unusual in any way for more than a few days, pay attention to the odor.
What this usually means: If it's not caused by a food that you've eaten, it could signal an infection in the bladder or kidneys. Less often, it's due to a metabolic disorder that reduces the body's ability to fully break down foods during digestion.
Uncontrolled diabetes can cause an abnormally sweet odor, and penicillin can cause a distinctive medicinal odor.
Even if you have no other symptoms, such as pain while urinating, but your urine continues to have an unusually strong smell for more than a couple of days, talk to your doctor.
Foamy or Bubbly
It's natural to see foam in the toilet when you really have to go and have a heavy stream. But urine that's consistently foamy or bubbly could mean that you're losing protein.
What this usually means: Kidney disease. Large amounts of protein in the urine is one of the main signs of chronic kidney disease. See your doctor right away.
Mucus or Cloudy
Mucus in urine could indicate inflammation in the urinary tract.
What this usually means: Urinary tract infection. See your doctor.
Cloudy urine also can be related to infection but often is just an indication that your urine is alkaline, which is harmless at low levels.
Volume and Frequency
The average adult typically urinates four to eight times in 24 hours. A change in the frequency of your urinary habits, including getting up more than twice a night to urinate, or an increase or decrease in the amount that you urinate, warrants attention.
What this usually means: An increase in the frequency of urination, along with an increase in volume, is one of the telltale signs of diabetes.
If the amount of urine seems the same but you're urinating more often, you could have a urinary tract infection. If this is the case, you'll probably have very strong urges to urinate even when just a small amount comes out.
Frequency of urination and/or urinary urgency in the absence of a urinary tract infection can indicate an overactive bladder.
In men, enlargement of the prostate gland can trigger urinary urgency. Patients with neurological conditions, such as multiple sclerosis, can also have this symptom.
Don't worry if there's been a decrease in the amount or frequency of urination. You probably just need to drink more water. If this doesn't help, see your doctor.