How To Diagnose a UTI the Right Way

Urinary tract infections (UTIs) can be frustrating, especially with the burning, the urgency, and the constant trips to the bathroom. But what’s worse is not knowing for sure if you actually have one. Getting the correct diagnosis is key to getting the proper treatment. However, not all UTI tests are created equal.

At-home test strips can give you a quick heads-up, but lab tests offer more precise answers. The three most common ways to test for a UTI are dipstick urinalysis, urine culture, and PCR testing. But each has its pros and cons.

Here’s what you need to know to make the best choice.

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Dipstick Urinalysis

If you want to get a quick check done for a UTI, dipstick urinalysis is convenient and gets the job done most of the time. It checks for signs of infection, like white blood cells, nitrites, or blood in your urine, which could indicate that bacteria are present. But the best part is that you can get results in minutes, whether at the doctor’s office or even at home [1-3].

When is it used?

When you visit your doctor complaining about that burning sensation or the non-stop urge to pee, they’ll first use the dipstick test. It’s a handy tool for a quick screening, especially when you need immediate results. Many people also use at-home dipstick tests as a pre-check before deciding to see a doctor [2-4].

Is dipstick urinalysis 100% accurate?

Dipstick tests don’t actually detect bacteria. They only look for signs of infection. The problem is that other conditions, such as kidney problems or menstruation, can cause similar results. This means you could end up taking antibiotics you don’t need if the test gives a false positive. On the other hand, a false negative might miss an actual infection, leaving you untreated [2-5].

A dipstick test can be a great first step, but it’s not the final word. If your symptoms stick around or get worse, it’s time for a lab-based test, such as a urine culture or PCR, to get a more accurate answer.

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Urine Culture

Urine culture is the go-to test for diagnosing a UTI, often called the “gold standard.”

With a urine culture, bacteria are grown from your urine sample in a lab to determine if an infection is present and to decide which antibiotics should be used to treat it [2], [3].

When is it used?

Doctors rely on urine cultures when they need a more definitive answer than a dipstick test can provide. If your symptoms are persistent or severe, this test helps confirm whether bacteria are causing the problem [2-4, 6].

The downsides

Urine culture only detects about 73% of UTIs. So, over a quarter of infections are missed. If multiple bacteria are present, some might not grow well enough to be identified. And the biggest drawback? The cost and the wait. Results take at least two or more days, delaying treatment while you’re stuck dealing with symptoms [2], [3], [6].

Urine culture is a powerful tool, but it’s not infallible. If your symptoms scream UTI but your test comes back negative, don’t ignore it — further testing might be needed.

Urine PCR

Urine polymerase chain reaction (PCR) is the premier diagnostic tool for UTI testing. A urine PCR doesn’t just look for bacteria; it amplifies their DNA for a precise diagnosis. Unlike traditional tests that rely on growing bacteria in a lab, PCR detects infections faster and with greater accuracy [4, 5].

When is it used?

With results in as little as 6 to 8 hours, PCR testing can speed up diagnosis and treatment. It’s particularly useful when a quick decision is needed, such as for recurrent UTIs or cases where standard tests give unclear results [4, 5, 7].

One significant advantage of PCR testing is that it can identify antibiotic-resistant strains of bacteria. This helps doctors pick the most effective antibiotic from the start [4, 5, 7].

Limitations to consider

While powerful, PCR tests only detect bacteria included in their test panel. That means if your infection is caused by an uncommon strain, it might not show up. Doctors also have to interpret results carefully, as detecting bacterial DNA doesn’t always mean an active infection [4, 5, 7, 8].

Urine PCR is highly accurate, and can guide targeted treatment, but it's not always the first choice due to cost and availability. If standard tests aren’t giving clear answers, this advanced option might be worth considering [4, 5, 7].