A urinary tract infection (UTI) is a common infection that occurs in the urinary system, which includes the bladder, ureters, and kidneys. Most UTIs involve the bladder and are thus categorized as lower urinary tract infections. UTIs are notably prevalent among women in the U.S., with about 40% of women experiencing at least one UTI in their lifetime.

Symptoms of UTIs in elderly patients may present uniquely, often as weakness, recurrent falls, and mental confusion. Without proper treatment, a UTI can progress, affecting the kidneys and potentially leading to abdominal pain, fever, mental confusion, and even septic shock. Indicators of a kidney infection, a more severe form of UTI, include severe pelvic pain, flank pain, chills, fever, and a fever of 100º or higher.

Upper urinary tract infections, such as pyelonephritis, may share symptoms with cystitis (bladder infections) but also include fever, rigors, flank or abdominal pain, nausea, and vomiting. In cases of recurrent UTIs, especially in female patients, a thorough abdominal and pelvic examination is recommended.

Different GI diagnoses can sometimes be confused with UTIs, such as renal colic, nephrolithiasis, trauma, pneumonia, pulmonary embolism (PE), and ruptured ovarian cysts. During physical exams for acute abdominal pain, certain findings might suggest an emergent cause, including UTIs.

Urinary tract infections are typically caused by bacteria that invade and inflame the urinary epithelium cells. The infection can start in the urethra and progress up to the bladder, ureters, or kidneys. Lower urinary tract infections affect the urethra or bladder, while upper tract infections can involve the kidneys.

UTIs can occur anywhere in the urinary tract, most commonly in the bladder and urethra. More serious are kidney infections. Triggers for UTIs include sexual activity and the use of catheters.

For 25% to 30% of women who have experienced a UTI, the infection returns within six months. Recurrent UTIs can significantly impact one’s life, but they are not typically due to poor hygiene or personal fault.

For further information on UTIs and their treatment, visit the Mayo Clinic Health System, Department of Urology, Hospital Handbook, and Harvard Health for detailed insights.