UTIs typically occur when bacteria enter the urinary tract through the urethra and begin to spread in the bladder. The urinary system is designed to keep out bacteria. But the defenses sometimes fail. When that happens, bacteria may take hold and grow into a full-blown infection in the urinary tract.
Symptoms include a persistent strong urge to urinate, a burning feeling when urinating, urinating often, cloudy looking urine, strong-smelling urine and pelvic pain, in women, especially in the center of the pelvis and around the area of the pubic bone
Urinary tract infections will usually not lead to complications if treated promptly and properly. But left untreated, UTIs can cause serious health problems.