Abstract image of hands touching, creating energy
Abstract image of hands touching, creating energy
Abstract image of hands touching, creating energy

Here comes the science bit…

Written by

Kayleigh Maxwell

Are you looking to find out more about at-home UTI testing with TestCard? 

The science behind TestCard is fairly straightforward. Here we’ll talk about what happens in your body when you get a urinary tract infection, signs of UTI in the urine, and how we can look for these signs.

What exactly is a UTI?

A urinary tract infection is an infection of the urethra, bladder, ureters, and/or kidneys (which together are known as the ‘urinary tract’ - the system through which urine is passed from the kidneys out of the body). A UTI is an infection caused by bacteria, which can find their way into the urinary tract for a number of reasons.

If harmful bacteria travel into the urinary tract and find themselves in an environment where they can grow and thrive, then they can invade and colonize cells, causing inflammation and infection.

How do you know if you have a UTI? 

Inflammation and infection of the urinary tract can give rise to a number of symptoms. The most common signs of a UTI include having a strong urge to pee, needing to pee often, and experiencing pain when you pee.

What if you’re not sure about your symptoms?

This is where urine dipstick testing using TestCard’s UTI test kit comes in handy. Dipstick testing uses urinalysis to check for certain substances in the urine which may indicate that you have a UTI.

The test kit itself is simple and easy to use. It involves only the test strip and the TestCard app, downloadable to your phone. You will be instructed to collect a urine sample, dip the test strip into the sample, and then use your phone to scan and interpret the results on the test strip.

If you would like a bit more information on how the kit works, check out our 4 simple steps for using the UTI test kit; we also have more information in our short article on using an at-home test kit.

What does the UTI test kit look for?

Here are the most important clinical signs of UTI which can be detected using the TestCard UTI test kit, and why they are important:

  • pH of the urine: Urinary pH is normally around 5 or 6, but when you have a UTI you will more likely have a urinary pH of 7 or more. There is a greater chance of bacteria causing an infection if the environment encourages their growth, and bacteria are more likely to grow in an environment with a less acidic pH. 

  • Nitrites in the urine: Nitrates (chemical compounds that we get mostly from foods e.g. leafy greens) can be found in normal, healthy urine, and are thought to play a part in keeping our bodies healthy and balanced. However, bacteria can transform nitrates into nitrites through a process of metabolism. So nitrites are a sign that there are uropathogenic (i.e. infection-causing) bacteria in the urinary tract.

  • Leukocytes in the urine: Leukocytes are white blood cells, which are used by the body to fight infection. If a significant amount of these are found, it is possible that your body is trying to fight off an infection in the urinary tract.

Deciding whether it’s a UTI

The TestCard test strip contains chemicals (called reagents) that will react with your urine sample and change colour depending on the content of the sample. 

The process of scanning the test strip with your phone uses colorimetry to determine the likelihood of UTI, in other words, deciding how likely it is that you have a UTI based on the colour of the pads on the test strips that have reacted with the nitrites, leukocytes etc. in the urine. These colours indicate how much of each substance has been detected, which is how you receive one of the following results:


Possible UTI

High Possibility

If you are experiencing symptoms of a UTI, it is important to get tested, which you can do with the TestCard UTI test kit (available at any of these pharmacies: Superdrug, Dears Pharmacy, Midway Pharmacy, Weldricks Pharmacy).

If your symptoms get worse or you begin to experience signs of a kidney infection (e.g. vomiting, fever, chills), it is important that you seek help from a medical professional straight away.