UTIs develop when bacteria - most commonly Escherichia coli (E. coli) from the gastrointestinal tract - enter the urinary system through the urethra. Several anatomical, behavioral, and medical factors can increase susceptibility.
In women, hormonal changes during menopause reduce protective vaginal flora, making infections more likely. Sexual activity can introduce bacteria into the urinary tract, and certain contraceptive methods such as diaphragms or spermicides alter the vaginal microbiome. In men, benign prostatic hyperplasia (BPH) can impede complete bladder emptying, creating a reservoir for bacterial growth.
Patients with diabetes, immunosuppressive conditions, urinary catheters, or structural abnormalities of the urinary tract face elevated risk. Kidney stones can obstruct urine flow and harbor bacteria, making stone patients particularly prone to complicated UTIs that require urological intervention.
