The truth about urine

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 colour, odour 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 Dr Tomas Griebling, a vice chair of the urology department at a university.

"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 Dr Anthony Smith, a professor and chief of urology at a university.

When you notice that your urine has changed colour, or there's a strange odour wafting up from the toilet, the cause might be something as harmless as what you had for dinner (which could have included beetroot 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.

Colour changes

Urine gets its yellow colour from a pigment called urochrome, also called urobilin. That colour 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 colour," 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 medicine that forces the body to get rid of excess water.

Urine can turn a rainbow of colours, 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 colour of port wine.

Seeing red is typically a sign that there is blood in the urine, but before you panic, remember that a little blood can produce a dramatic colour 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, such as an infection or cancer, and it warrants a visit to your doctor. If you're seeing blood and your urine is also cloudy, there's a good chance you've picked up an infection, Smith says.