Why does my pee smell?

Pee-yew! Do you sometimes notice your urine smells more than usual? The smell of our pee can often tell us lots of things about our health. But don’t get your knickers in a knot, not all stronger urine smells are a cause for concern.

What causes your pee to smell?

Watch Medibank expert Dr Zoe Boyatzis explain what causes urine to smell, and when you might want to go to the doctor for a checkup.

Eating certain foods, taking some medications or being dehydrated can alter the smell of your urine.

Everyone’s urine is unique and you might notice your urine smells stronger sometimes, particularly after consuming Brussels sprouts, garlic, coffee and tea, with asparagus being the worst offender. But why? Scientists still aren’t entirely sure why asparagus makes our pee smell, but the current schools of thought suggest that either some people carry a gene that cannot break down the proteins in asparagus, or that everyone's urine undergoes a change in smell, but only some can detect it.

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Is smelly pee a cause for concern?

In more serious cases, a strong urine odour may indicate an underlying issue with the most common including:

• Urinary Tract Infection (UTI) may cause your urine to smell a little more than usual due to the mix of mucus and white blood cells associated with the infection. You may also notice the colour of your pee changing from clear to cloudy. Visit your doctor if you have the urge to urinate more frequently or if you experience a burning sensation.
• Diabetes may result in sweet smelling urine due to high blood sugar from your body not being able to process sugars. Be sure to visit your GP if you experience this symptom as untreated diabetes can be life threatening.
• Dehydration can cause your urine to smell like ammonia and become more concentrated in colour. This can be treated by drinking lots of fluids. If you are experiencing symptoms like fatigue, confusion and weakness, you could be experiencing extreme dehydration and should seek immediate medical attention.

While the smell is undetectable to humans, some dogs can even detect cancer simply by smelling urine samples. While further study is required, a recent study found trained dogs were able to detect prostate cancer in urine samples with 98 - 100% accuracy.

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When should I see a doctor?

Most changes in your urine odour are temporary and don’t necessarily mean you have a serious illness. Visit your doctor if the odour hasn’t gone away after 12 hours or it’s accompanied by other symptoms like cloudy or bloody urine or a burning and painful feeling.

Learn more about common health conditions in our What Causes series here.