Diagnosing a UTI involves examining a urine sample to detect the presence of bacteria or using imaging tests to diagnose other underlying causes. Usually, experiencing symptoms prompts a doctor to order tests.

UTIs are common infections that happen when bacteria enter the urethra and infect the urinary tract. This can lead to discomfort, pain, and, in severe cases, complications such as kidney damage.

This is why timely and accurate diagnosis is crucial for effective treatment and prevention of complications.

In this article, we explore the various diagnostic tests that doctors use to diagnose UTIs. We also look at UTI treatment and answer some commonly asked questions.

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If a person suspects they have a UTI or are experiencing unusual symptoms, they should visit a healthcare professional.

A healthcare professional will be able to determine the underlying cause and recommend some of the tests that this article later discusses.

Some symptoms to look out for include:

  • urinary urgency
  • frequent urination
  • dysuria, or painful urination
  • blood in the urine

Learn about UTI and its symptoms.

Diagnosing a UTI usually involves a urine test. This requires obtaining a urine sample, which a doctor then examines for the presence of:

There is minimal preparation for a urine test. However, drinking plenty of water and avoiding using the toilet immediately beforehand can help.

When doing a urine test, a doctor may request a “clean catch” to prevent contaminating the sample with bacteria from the skin. To do this, a person will need to wait until after their initial flow to start collecting the urine.

A positive result for the presence of bacteria or a higher white blood cell count typically confirms the diagnosis of a UTI.

In some cases, healthcare professionals may recommend imaging tests to assess the urinary tract for abnormalities. These tests can help determine whether anatomical or functional complications are the cause.

Imaging provides detailed pictures of the kidneys, bladder, and other urinary structures, helping to identify underlying causes of UTIs.

Tests may include:


An ultrasound — also known as a sonogram — uses a hand-held device known as a transducer to bounce high-frequency sound waves off organs to create images of their structure.

A sonographer will apply lubricating gel to the person’s skin and place the transducer on the abdomen to perform an external ultrasound. The transducer transmits images of the kidneys and bladder to a computer monitor, allowing a doctor to detect any abnormalities, such as those that may be causing a UTI.

To scan the urinary system, a sonographer may perform an internal ultrasound. To do this, they will gently place the small transducer with a sterile cover into the rectum for a male or into the vagina for a female.

CT scan

A computerized tomography (CT) scan combines data from various X-rays with computer technology to create two-dimensional (2D) or three-dimensional (3D) images. These scans can show stones and infections in the urinary tract, cysts, tumors, and traumatic injuries.

During a CT scan, the patient must lie down very still on a motorized examination table that slides into a circular CT scanner machine. After one X-ray picture, the couch will move slightly and the machine will take another image, and so on.

MRU scan

A magnetic resonance urography (MRU) is a type of MRI scan that doctors use to evaluate and identify abnormalities in patients with recurrent UTIs. They use a strong magnetic field and radio waves to create detailed images of the organs and tissues within the body.

During an MRI scan, a person lies inside a large tube-like scanning machine. It is vital to stay still, as any movement can disrupt the images. The scan provides images of the urinary tract and surrounding structures. Unlike CT, MRI does not involve exposure to ionizing radiation.

For recurrent or persistent UTIs, a healthcare professional may recommend a cystoscopy or ureteroscopy. These procedures involve inserting a thin, flexible tube with a camera into the urinary tract to visually inspect the bladder, urethra, and other structures for signs of infection or abnormalities.

Scopes can help doctors identify the causes of recurrent UTIs, such as:

  • stones
  • obstructions
  • lesions in the bladder

People can expect to feel some discomfort after a cystoscopy and, for up to 2 days, may experience a burning sensation while urinating or notice small amounts of blood in the urine.

Once a doctor diagnoses a UTI, prompt treatment is essential to alleviate symptoms and prevent complications. Treatment usually involves a course of antibiotics to kill the bacteria causing the infection.

The choice of antibiotic depends on factors such as:

  • the severity of the infection
  • the type of bacteria involved
  • any underlying health conditions

It is vital to complete the full course of antibiotics a doctor prescribes, even if symptoms are no longer present. This can help ensure the infection is fully cleared.

Alongside antibiotics, healthcare professionals may recommend over-the-counter pain relievers, such as ibuprofen, to alleviate discomfort that occurs with UTI symptoms, such as pain and fever.

Drinking plenty of fluids and avoiding irritants, such as caffeine and alcohol, can also help flush out bacteria from the urinary tract and promote healing.

Below are answers to common questions about UTI diagnosis.

How can UTIs be diagnosed?

A doctor typically diagnoses a UTI through a urine test, which detects the presence of bacteria and other indicators of infection.

What are the three symptoms of a UTI?

The three most common symptoms of a UTI are frequent urination, a burning sensation during urination, and cloudy or strong-smelling urine.

What are the symptoms of a sudden UTI?

Symptoms of a sudden UTI may include sudden onset of urinary urgency, discomfort or pain in the lower abdomen or pelvic region, and fever.

Diagnosing a UTI involves a combination of clinical evaluation and diagnostic tests such as urine analysis, imaging studies, and scopes. Prompt diagnosis and treatment are crucial for managing UTIs and preventing complications.

If an individual experiences symptoms of a UTI, such as frequent urination or blood in the urine, it is important to seek medical attention promptly for proper evaluation and treatment. With appropriate care, doctors can treat most UTIs successfully, relieving symptoms and restoring urinary tract health.