Causes and Risk Factors
Most UTIs occur when bacteria from the digestive tract - usually E. coli - enter the urethra and multiply in the bladder. Risk factors include:- Female anatomy: A shorter urethra gives bacteria a shorter path to the bladder.
- Sexual activity: Intercourse can move bacteria toward the urethral opening.
- Menopause: Falling estrogen levels thin the urinary and vaginal tissues, a change known as genitourinary syndrome of menopause, making infection more likely.
- Blocked or incomplete urine flow: An enlarged prostate (benign prostatic hyperplasia) or kidney stones can trap urine in the bladder, where bacteria grow.
- Medical conditions: Diabetes and other conditions that weaken immune defenses increase risk, as do urinary catheters.
Symptoms
Bladder infection symptoms tend to come on quickly and may include:- Burning or pain with urination: Often the first and most noticeable symptom.
- Urgency and frequency: A strong, persistent urge to urinate, often passing only small amounts.
- Changes in the urine: Cloudy, strong-smelling, or pink-tinged urine.
- Pelvic pressure: Discomfort in the center of the pelvis or lower abdomen.
- Low-back or lower-abdominal ache: A dull ache can accompany bladder irritation even without fever.
Diagnosis
A urinalysis checks for white blood cells, red blood cells, and bacteria, and a urine culture identifies the specific organism and which antibiotics will work against it. For healthy younger women with classic symptoms, treatment often starts right away; for men, pregnant women, and anyone with recurrent infections, the culture is especially important because it confirms the diagnosis and steers antibiotic choice. If infections keep returning, or if a structural problem is suspected, your physician may order imaging of the urinary tract or refer you for further evaluation.Treatment
Treatment depends on where the infection is and whether it is complicated:- Antibiotics: Uncomplicated bladder infections usually respond to a short course of an antibiotic such as trimethoprim-sulfamethoxazole or cephalexin. Fluoroquinolones such as ciprofloxacin are generally reserved for kidney infections or complicated cases.
- Supportive care: Drinking plenty of water helps flush bacteria, and a heating pad can ease pelvic discomfort.
- Prevention of recurrences: Staying hydrated, urinating after intercourse, and - for postmenopausal women with repeated infections - low-dose vaginal estrogen can meaningfully reduce recurrences. Cranberry products are safe to try, though the evidence for them is mixed. Some patients benefit from other preventive antibiotic strategies, which your physician can tailor to you.