A UTI happens when bacteria — usually from the bowel — enter the urinary tract (bladder, kidneys, ureters, or urethra) and multiply, causing infection. Most UTIs affect the bladder and are easily treated, but if bacteria travel up to the kidneys the infection becomes more serious. Some people get infections repeatedly — called recurrent UTI.
About 6 in 10 women and 1 in 10 men will have at least one UTI in their lifetime (Urology Care Foundation). Recurrent UTI (3+ infections a year, or 2+ in six months) affects 20–30% of women who've had one already.
Causes & risk factors
- Female anatomy (a shorter urethra, closer to bacterial sources)
- Sexual activity or frequent intercourse
- Menopause and low oestrogen, thinning vaginal/urethral tissue
- Diabetes, weakened immunity, or kidney stones
- Urinary catheters or incomplete bladder emptying (enlarged prostate, neurogenic bladder)
- Structural abnormalities of the urinary tract
Symptoms to watch for
- Burning pain with urination
- Frequent, urgent need to urinate, often passing very little
- Cloudy, bloody, or strong-smelling urine
- Pelvic or lower abdominal pressure
- Fever, chills, nausea/vomiting, or flank pain may signal a kidney infection needing urgent care
How it's diagnosed
- Urinalysis (dipstick/microscopy for bacteria, white cells, blood)
- Urine culture to identify the bacteria and the right antibiotic
- Imaging (ultrasound/CT) if recurrent or complicated
- Cystoscopy for recurrent cases, to check for a structural cause
Treatment options
- Short-course antibiotics: the standard first-line treatment for a simple UTI.
- Longer or IV antibiotics: for kidney infections or complicated UTIs.
- Low-dose preventive antibiotics: for people with frequent recurrences.
- Vaginal oestrogen therapy: for postmenopausal women with recurrent UTIs.
- Behavioural prevention: more fluids, and voiding after intercourse.
- Surgical correction: only if an anatomical blockage or stone is the underlying cause.
Outlook & prevention
Most UTIs clear completely with appropriate antibiotics within a few days. Staying well-hydrated, urinating after intercourse, and not delaying urination all reduce risk; recurrent UTI is manageable with preventive strategies and evaluation for an underlying cause.
- Fever, chills, or back/flank pain along with urinary symptoms (possible kidney infection)
- Blood in urine, or symptoms not improving after 2–3 days of treatment
- 3 or more UTIs in a year — warrants evaluation for recurrent UTI