Causes and Diagnoses

Causes and Diagnosis of Urinary Tract Infections

Normal urine is sterile, without any bacteria or fungi. A UTI happens when germs, often from the digestive tract, travel through the urethra and into the bladder.

Most UTIs are caused by E. coli bacteria, which occur naturally in the digestive tract.

Diagnosing UTIs

Your physician will review your medical history and perform a physical exam. Other tests may include:

  • A urinalysis to detect blood cells, germs (like bacteria) or excess protein in the urine.
  • A urine culture through which a lab will attempt to grow potential bacteria or yeast found in the urine to help in diagnosis and treatment.

If UTIs become a repeated problem, other tests may be used to see if the urinary tract is normal. These tests may include:

  • Cystourethroscopy also known as a cystoscopy, to examine the inside of your bladder and urethra. It is often used to diagnose and evaluate urinary tract disorders, such as urinary tract inflammation, bladder stones and bladder tumors.
  • Kidney and bladder ultrasound to show the size and shape of the bladder and kidneys through high-frequency sound waves. This test can locate a mass, stones, cysts, blockages and abnormalities.
  • CT scan to make detailed images of the urinary tract through the use of X-rays and a computer.