To diagnose a urinary tract infection, or UTI, a provider may ask about urinary symptoms and then order a urine sample. Alternatively, they may simply treat your symptoms as if a UTI exists without testing. The urine test will look for the presence of bacteria as well as white blood cells and other chemicals that signify the presence of an infection. Because bacteria can also be found in the urine of healthy individuals, diagnosis is based on both the symptoms and the laboratory test.
The urine test is performed on a “clean catch” sample, meaning that the genital area must be washed first and the sample collected “midstream.” This helps prevent bacteria around the genital area from getting into the sample and confusing the test results. Alternatively, a catheter may be introduced during an exam to obtain urine for a test.
For women with recurrent UTIs, the urine may be cultured to clearly identify the bacteria, which can help determine what antibiotic to use for treatment. They may also have additional tests to see if their urinary tract is normal. These tests may include:
- Kidney and bladder ultrasound: An ultrasound uses sound waves to create an image of internal organs. The images can show structural abnormalities with the kidneys and bladder.
- Voiding cystourethrogram: An x-ray image of the bladder and urethra is taken while the bladder is full and during urination, or voiding. A thin, flexible tube called a catheter is inserted through the urethra into the bladder, and fills the bladder and urethra with a special dye to make the structures clearly visible on the x-ray images. After x-rays are taken from various angles, the catheter is removed and x-rays are taken during urination. This test can show abnormalities on the inside of the urethra and bladder.
- CT scan: CT scans create three-dimensional images of internal organs. They can provide clearer, more detailed images of the kidneys, ureters, bladder, and urethra.
- MRI: Magnetic resonance imaging, or MRI, uses radio waves and magnets to produce detailed images of internal organs and soft tissues.
- Urodynamics: Any procedure that examines how well the bladder, sphincters, and urethra are storing and releasing urine is considered urodynamic testing. Most urodynamic tests focus on the bladder’s function.
- Cystoscopy: This procedure uses a tube-like instrument to look inside the urethra and bladder. Local anesthesic jelly is often used. In some cases, sedation or general anesthesia may be required. Cystoscopy can reveal swelling, redness, and other signs of infection.