Learn how to test & detect a UTI: How do doctors test for UTIs?

Written by

Kayleigh Maxwell

Urine dipstick test (rapid urine test)

Two of the most common approaches used by doctors for UTI testing are urine culture, and dipstick urine testing. The test that they use may depend on your symptoms and medical history. (1)

A rapid urine test involves placing a dipstick into a sample of urine. The dipstick changes colour depending on the level of particular substances that are present in the urine.

What can be detected by a urine test?

Key substances which can be detected by dipstick urine tests include nitrites, leukocytes, ketones, sugar and protein. (2)

What is the significance of nitrites being present in urine?

You can find nitrites in urine when particular bacteria are present. There are certain harmful bacterial species that produce an enzyme which converts nitrates into nitrites, so this is an important sign of bacterial infection. (3)

What causes Leukocytes in urine?

Leukocytes are white blood cells, which are key in the body’s immune response to infection. If a dipstick test shows that you have a high count of leukocytes, it is possible that you have a urinary tract infection. (3)

What do high pH levels in a routine urine test mean?

Having a urinary pH level of around 5 or 6 is considered healthy. If the pH level is under 5, this is a sign that the urine is too acidic, and above 5 indicates that the urine is too alkaline. With cystitis, the pH level is often over 7. (1)

What causes high ketones in urine?

Ketones are not usually found in urine. They are a sign of high blood sugar, and are normally an indicator of diabetes rather than urinary tract infection. (1)

That being said, ketones can also be found when the body is burning fat instead of sugar. This can happen with weight loss - you may have heard of the ‘keto’ diet, which involves the process of ketosis (burning fat instead of carbohydrates). (3)

What does protein and urobilinogen in urine mean?

Protein is often a sign that there is something wrong with the kidneys, but it can also be associated with lower UTI (of the bladder or urethra). (3)

Urobilinogen is not normally found in urine and can be indicative of problems with the liver, or other health issues. 3

The biggest indicators of urinary tract infection are, pH, leukocytes and nitrites. It has been suggested that if a dipstick test shows negative for leukocytes then infection is extremely unlikely, whereas a significant amount of nitrites is a very strong indicator for UTI. (4)   

Urine culture

Alternatively, a doctor might test for UTI by sending your urine sample to a lab to be cultured. At the lab, any infection-causing bacteria within the sample will be allowed to grow over a period of 24-48 hours. If bacteria has grown by the end of the incubation period, further tests can be conducted to figure out which bacterial species are present, and which antibiotic will be the most effective at treating the infection. (1,3)

Do doctors use the same testing as an at-home UTI test kit?

If you have UTI symptoms such as cloudy urine, a stinging or burning feeling when you pee, or you keep needing to pee more than usual, you might want to visit your doctor. The doctor will take note of your symptoms, and may then want to test a urine sample for further signs of an infection. They will normally do this with either a dipstick test or a urine culture.


You can also opt to do a dipstick test for UTI from the comfort of your own home with an at-home UTI test kit, which works exactly the same as the dipstick test the doctor would use. You can do this with the TestCard UTI test kit (available at weldricks.co.uk, alphega-pharmacy.co.uk, zavamed.com and at Superdrug.com). 

How does this work? The TestCard UTI test kit is delivered straight to your door. You will test a urine sample and get results straight away, and if your test is positive you can also use our treatment partner to get antibiotic treatment sent to you. 

1 https://www.ncbi.nlm.nih.gov/books/NBK279350/

2 Schmiemann, G., Kniehl, E., Gebhardt, K., Matejczyk, M. M., & Hummers-Pradier, E. (2010). The diagnosis of urinary tract infection: a systematic review. Deutsches Ärzteblatt International, 107(21), 361.

3 https://liveutifree.com/at-home-uti-test/

4 Bafna, P., Deepanjali, S., Mandal, J., Balamurugan, N., Swaminathan, R. P., & Kadhiravan, T. (2020). Reevaluating the true diagnostic accuracy of dipstick tests to diagnose urinary tract infection using Bayesian latent class analysis. PloS one, 15(12), e0244870