Above: Image © CSA-Printstock, iStockshoto

Taking a leak. Number one. Going pee. These are just some of the ways to describe something you do everyday, probably without giving it much thought. Urinating might seem like an ordinary act. But the way your body produces urine and what your urine says about your health are pretty extraordinary!

Did you know? Urinalysis is one of the oldest medical diagnostic tools, dating back as far as 6000 years.

How does your body make urine?

All of your organs have specific roles in keeping you alive and healthy. For example, your heart pumps blood to the rest of your body. Your liver detoxifies chemicals and regulates energy supplies. Your kidneys filter waste out of your blood and put it into a liquid that can be excreted. As you probably guessed, that liquid is called urine!

Your kidneys make sure your blood always has the right concentrations of essential nutrients, and as few toxins as possible. This is no easy feat! The kidneys fulfil their duty with the help of specialized structures called nephrons.

Nephrons begin by filtering your blood. Blood cells and proteins are too large to pass through the filter. They get sent to an area of the nephron called the Bowman’s capsule. From there, they continue along the vasculature of the kidney and eventually re-enter the bloodstream.

The liquid that passes through the filter is called the filtrate. It is made up of all the substances small enough to pass through the filter. The filtrate continues on its journey through the tubules (tiny tubes) that make up the rest of the nephron.

Depending on what’s happening in your body, substances may be added or removed as the filtrate gets processed. For example, if you are very dehydrated, almost all of the water in the filtrate will be sent back into your bloodstream. This will help maintain a healthy blood pressure.

When everything that needs to be added has been added, and everything that needs to be removed is removed, the filtrate reaches the end of the nephron and can officially be called urine!

Did you know? A single kidney contains around one million nephrons! These specialized structures help make sure your blood contains just the right balance of nutrients.

You can learn a lot from urine!

Has your doctor ever asked you to pee in a cup? This can be a little awkward. But that tiny cup of urine can provide your doctor with important information on your health!

Your kidneys are responsible for making urine. So the composition of your urine says a lot about your kidney function. Anything out of the ordinary can suggest kidney problems. For example, urea is a substance that helps your body metabolize certain compounds. Too much or too little urea—or abnormal levels of urea ions like potassium, sodium, or chloride—can be a sign of kidney problems.

There are many other conditions that a urine sample can help diagnose. The presence of blood can an early sign of kidney or bladder cancer. The presence of glucose (sugar) in urine can be a sign of diabetes. The presence of bacteria can be a sign of urinary tract infections or sexually transmitted infections, such as chlamydia and gonorrhoeae.

But wait...there’s more! In drug tests, urine samples are used to look for metabolites of certain drugs. And in pregnancy tests, urine samples are tested for a protein called human chorionic gonadotropin, which is only present in pregnant women. Finally, more sophisticated technologies are allowing scientists to take urinalysis even further. Tests can now detect microscopic markers for illnesses like tuberculosis.

Did you know? The yellow colour of urine comes from urochrome, which is created when your body breaks down hemoglobin (the main protein in red blood cells).

A rainbow you definitely don’t want to taste

You don’t have to wait until your next doctor’s appointment to get information from your urine. You can draw some conclusions yourself with a simple visual inspection.

Let’s start with colour and clarity. If your urine is dark yellow or orange, you’re likely dehydrated. Try drinking more water. If your urine is very clear or transparent, you could be drinking too much water. Yes, overhydration is a thing and it can disturb your electrolyte balance. However, clear urine can also simply be a sign that you’re well-hydrated. If your urine is persistently cloudy, a trip to the doctor might be a good idea. Cloudy pee can signal an infection or the early stages of kidney stones.

Sometimes you can even smell out a health issue. If your urine smells sweet, musty or particularly foul, get it checked! But before you freak out, remember that certain foods like asparagus, beets, and sugar crisp cereal can alter the smell and colour of your urine temporarily. This is completely normal, and no cause for alarm.

Who would have thought that something as simple as a cup of pee could be so important. That cup could help diagnose medical conditions from dehydration to cancer. So the next time you’re at the doctor’s office and they hand you a sample container, don’t cringe! Instead, think of your urine sample as a golden ticket to your health status.

Learn More!

About urine and health:

What Your Pee Is Telling You (2015)
T. Sukkarieh MD, Everyday Health

What the color of your urine says about you (infographic) (2013)
Urinary and Kidney Team, Cleveland Clinic

Urine formation
About Kid’s Health, The Hospital for Sick Children

About scientific studies on urine:

Urine as a specimen to diagnose infections in twenty-first century: focus on analytical accuracy (2015)
T. Tuuminen, Frontiers in Immunology 3

Looking at the Urine: The renaissance of an unbroken tradition (2007)
G. Eknoyan, American Journal of Kidney Disease 49
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Detection of early pregnancy forms of human chorionic gonadotropin by home pregnancy test devices (2001)
S. A. Butler, S. A. Khanlian & L. A. Cole, Clinical Chemistry 47

Evaluation of a dipstick test for glucose in urine (1976)
J. Dyerberg, L. Pedersen & O. Aagaard, Clinical Chemistry 22
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Kira Genise


At the University of Ottawa, I completed a degree in Biomedical Sciences with a minor in Psychology. During my studies I developed a passion for studying areas of science that occur on microscopic levels, such as molecular biology, microbiology and pharmacology. Eventually I hope to continue my education in the healthcare field. I also believe that outside is the best side! I enjoy hiking, camping and playing sports in the great outdoors in my spare time.

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