The Truth About Urine
What do urine color and odor changes mean? How often should you 'go'? Find out.
By Stephanie Watson
WebMD FeatureReviewed by Louise Chang, MD
March 11, 2010
Urine isn't something most people talk about. We barely give it more than a passing glance as it swirls out of sight down the toilet bowl. Yet changes in the urine – its color, odor, and consistency – can provide important clues about the status of your body. Your urine can reveal what you've been eating, how much you've been drinking, and what diseases you have.
"Urine and urinalysis have, for hundreds of years, been one of the ways physicians have looked at health," says Tomas Griebling, MD, MPH, vice chair of the urology department at the University of Kansas.
"From a historical view, urinalysis was one of the original windows into what's happening in the body," Griebling says. That's because many of the substances circulating in your body, including bacteria, yeast, excess protein and sugar, eventually make their way into the urine.
Urine is an important part of the body's disposal process. Its job is to remove the extra water and water-soluble wastes the kidneys filter out of the blood. "The urine is there primarily to get rid of toxins or things that would otherwise build up in the body that would be bad for the body," says Anthony Smith, MD, professor and chief of urology at the University of New Mexico.
When you notice that your urine has changed color, or there's a strange odor wafting up from the toilet, the cause might be something as harmless as what you had for dinner (which could have included beets or asparagus). It also might be a sign of a more serious condition, such as an infection or cancer.
Before you flush, here are a few urine changes to look out for, and what they might be saying about your health.
Urine gets its yellow color from a pigment called urochrome. That color normally varies from pale yellow to deep amber, depending on the concentration of the urine. Darker urine is usually a sign that you're not drinking enough fluid. "Your body needs a certain amount of fluid to function, so the body will hold on to fluid and the urine will become very strong and concentrated. When that happens, it will turn a darker color," Griebling says.
The opposite is also true. If your urine is very pale, it means that you're either drinking a lot of fluid, or you're taking a diuretic -- a drug that forces the body to get rid of excess water.
Urine can turn a rainbow of colors, and an unusual hue isn't necessarily cause for alarm. Certain medications can turn the urine fluorescent green or blue, carrots can tint it orange, vitamins can give it a yellow hue, and an inherited disease called porphyria can shade it the color of port wine.
Seeing red is typically a sign that there is blood in the urine, but before you panic, know that a little blood can produce a dramatic color change. "What I always tell patients is it takes one drop of blood to turn a toilet bowl red," Smith says.
That said, just a little blood in the urine can be a sign of something serious, like an infection or cancer, and it warrants a visit to your doctor or urologist. If you're seeing blood and your urine is also cloudy, there's a good chance you've picked up an infection, Smith says.
Urine normally doesn't have a very strong smell. If you get a whiff of something particularly pungent, you could have an infection or urinary stones, which can create an ammonia-like odor. Diabetics might notice that their urine smells sweet, because of excess sugar. In the past, doctors would actually taste urine for this sweetness to diagnose diabetes.
Some foods can also change urine odor. Asparagus is among the most notorious. What people are smelling when they eat asparagus is the breakdown of a sulfur compound called methyl mercaptan (the same compound found in garlic and skunk secretions). If you catch a whiff of something after eating a plate of asparagus, it means that you've inherited the gene for the enzyme that breaks down mercaptan. Not everyone has this enzyme and, therefore, not everyone can smell it.
How Often Do You Need to Go?
How often you need to go can be as important an indicator of your health as the color or smell of your urine. Most people take bathroom breaks about six to eight times a day, but you might go more or less depending on how much fluid you drink. If you're constantly feeling the urge to go and it's not because you're not drinking extra fluid, causes can include:
Overactive bladder -- involuntary contractions of the bladder muscle
Urinary tract infection
Interstitial cystitis -- a condition that causes the bladder wall to become inflamed and irritated
Benign prostate enlargement -- growth of the prostate that causes it to squeeze the urethra and block the normal flow of urine out of the body
Neurological diseases, including stroke and Parkinson's disease
The opposite problem -- not going to the bathroom enough -- can occur when there is a blockage or infection. Or, it can be the result of bad bathroom habits. Some people -- especially teachers, surgeons, and anyone else who doesn't have time for regular bathroom breaks throughout the day -- tend to hold it in.
Delaying urination can be problematic, says Smith, who compares the bladder to a Slinky: It stretches and then contracts repeatedly, but eventually it can stretch too much to bounce back. "The bladder can develop a chronic overdistension…a chronic emptying problem," he says.
Developing Healthy Bathroom Habits
Take good care of your bladder, and it will thank you by helping you urinate regularly. To avoid having to make too many bathroom visits, stay hydrated, but not overhydrated. Drink whenever you're thirsty, but don't feel as though you have to adhere to the eight-glasses-a-day recommendation (unless you have kidney or bladder stones, in which case you'll need to increase your fluid intake).
If you're getting up during the night to use the bathroom, stop drinking three to four hours before bedtime. Limit caffeine, which can irritate the lining of the bladder. Also watch your intake of alcohol, which can have similar effects.
Finally, don't hold it in. As soon as you feel the urge to go, excuse yourself from whatever you're doing and find a bathroom.