Colour of urine can tell a lot about your overall health
By Sheryl Ubelacker
TORONTO – It’s something we all get rid of several times a day – and sometimes in the middle of the night – but it’s not exactly a topic of everyday or, let’s face it, polite conversation.
Still, urine, pee – call it what you will – can tell a lot about a person’s health, especially when it comes to colour.
Urine is comprised of waste products and excess fluid that are filtered from the blood by the kidneys. When healthy, these twin fist-sized organs filter up to about 150 litres of blood each day, producing one to two litres of urine that is passed through the tube-like ureters to the bladder for elimination through the urethra.
How much urine an individual produces depends on many factors, including the amount of liquids and types of foods ingested and how much fluid is lost through perspiration and respiration.
Ever wonder why urine can look amber-coloured in the morning, but range from straw to sunshine yellow at different times throughout the day?
It’s all to do with the amount of water and other liquids a person consumes at any given time, says urologist Dr. Daniel Shoskes of the Cleveland Clinic, which has created an online chart entitled “The Colour of Pee.”
“People may wonder why their urine is a little dark or a little lighter,” says Shoskes, who served as a consultant on the project.
“What the chart sort of helps with is first of all with all the variations of yellow, from very pale to very dark,” he says. “It’s a measure of hydration. So certainly the more you drink, the closer to water it’s going to look like.”
Indeed, if the urine is colourless, doctors at the Cleveland Clinic who created the chart suggest the person is drinking a lot of water and “may want to cut back.”
Pee that’s reminiscent of pale straw or a transparent yellow is considered normal. A slightly darker sunshine yellow is also in the normal range, but the chart recommends drinking some water “soon.”
Seeing amber- or honey-coloured urine is an indication the body isn’t getting adequate water. “Drink some now,” the chart recommends.
Urine can be darker in the morning because it’s more concentrated, says the American-born Shoskes, who grew up in Toronto and did his medical training at the University of Toronto, followed by a research fellowship at the University of Alberta.
“That’s natural. If you sleep for eight hours, you’re not drinking for eight hours, then you’re going to be relatively dehydrated when you wake up … If you’re very dehydrated, healthy kidneys are very good at being able to conserve water and concentrate urine, so it gets a lot darker.
“And I think the chart shows that that’s pretty much a normal thing.”
What isn’t normal is urine that passes out of the yellow end of the spectrum into various other colours of the rainbow.
Urine that looks like a bottle of dark ale or syrup could indicate severe dehydration or liver disease. If drinking lots of water fails to eliminate the brownish hue and the colour persists, a visit to the doctor is called for.
Pink to reddish urine should raise a red flag – or at least start one wondering what’s been recently ingested that might account for that blush of colour.
“When unusual colours come out, fortunately sometimes it’s just in response to certain foods and everyone reacts differently,” says Shoskes, a surgeon who specializes in kidney transplants. “I know if I eat fresh beets, I’m going to have red urine that day. That’s me, but that’s not other people.”
Confirmed: Urine Is Not Sterile
The popular notion that urine is sterile is a myth, new research finds.
Yes, the myth that comes up every time someone pees in a pool (or drinking water reservoir) is actually false. In fact, bacteria do live in urine, Loyola University researchers reported this week at the general meeting of the American Society for Microbiology in Boston.
Some of the bacteria may even be linked to certain bladderconditions that have long been believed to be neuromuscular, not infectious, in origin.
"We need to reassess everything we think we know about urine," study researcher Evann Hilt, a graduate student at Loyola, told Live Science.
For years, even doctors believed urine was sterile. The myth goes back 50 years, Hilt said, when a screening method for kidney infections was developed. It was a simple and easy test that was soon applied to bladder infections, too.
But the test involved culturing only a small amount of urine in open air, at a temperature of 95 degrees Fahrenheit (35 degrees Celsius) for 24 hours. Not all bacteria grow in those conditions. [Gallery: Bacteria in Your Belly Button]
Hilt and her colleagues suspected bacteria might be present in healthy urine because a previous Loyola study found bacterial DNA in healthy urine. But those results, published in April 2012 in the Journal of Clinical Microbiology, did not prove that the bacteria were living.
To get to the bottom of the mystery, the researchers cultured urine (collected via catheter) on various substrates and in different conditions, such as without oxygen or with more carbon dioxide. If the original test was like a single seed planted in sandy soil in full sun, this new version was like planting 100 seeds in a variety of soils and locations. The researchers also let the bacteria grow for 48 hours, not just 24.
They found whole swaths of bacteria not detected before in healthy urine, simply because no one had ever looked.
Link to disorders?
The urine in the study came from patients at a clinic, including some with overactive bladder, a disorder that causes the sudden, frequent and urgent need to pee. Some bacteria seen in the study were more common in patients with overactive bladder than in women without urinary issues, suggesting these germs may play a role in the disorder.
"We don't know if they're a consequence of overactive bladder or if they are a cause of overactive bladder," Hilt said. "We still have to perform more studies."
But about 15 percent of women have overactive bladder, and about half aren't helped by medications that target their muscles and nerves, Hilt added.
Among the bacteria discovered was Actinobaculum schaalii, which is known to sometimes cause infections in the lower urinary tract (though the women in this study did not have urinary tract infections). Another was Aerococcus urinae, which can cause urinary and heart infections, particularly in the elderly.
Medical researchers are very excited about studying the microbiome, or the bacterial populations that live in and on the human body.
"We want to know who is good, who is bad, how they interact with one another and how they interact with the host," she said.