A UTI is usually caused by bacteria entering the urinary tract , most often E. coli from the bowel or skin, and then multiplying in the bladder or urethra. It’s more common in women because the urethra is shorter and closer to the rectum, which makes it easier for bacteria to get in.

Common causes

  • Bacteria spreading from the rectum or skin into the urethra.
  • Sexual activity, which can move bacteria toward the urethra.
  • Not emptying the bladder fully, or holding urine too long.
  • Catheters or urinary blockage, such as a kidney stone or enlarged prostate.
  • Changes in vaginal bacteria, including menopause or spermicides.

Less common causes

  • Other bacteria besides E. coli can cause UTIs.
  • In some cases, fungi or certain sexually transmitted infections can cause UTI-like symptoms.

When to get help

Burning when peeing, frequent urination, urgency, cloudy urine, blood in urine, fever, or back pain can all point to a UTI and should be checked by a clinician, especially if symptoms are severe or keep coming back.

Prevention basics

  • Drink enough fluids.
  • Urinate after sex.
  • Avoid douching or harsh genital products.
  • Wipe front to back.

If you want, I can also explain UTI symptoms, treatment, or prevention in plain language.