Urinary tract infections (UTIs) are the most common type of infection in women and affect up to 40% of them in their lifetime; UTI can be classified as uncomplicated (localized to the bladder, known as cystitis), or complicated (involving the kidneys and other structures). The most common bacteria that causes uncomplicated UTIs is Escherichia coli; more severe symptoms occur in complicated cases, particularly in people with certain risk factors.

The main signs and symptoms of urinary tract infections include pain or burning during urination, fever, frequent urges to urinate, lower stomach discomfort, and changes in urine appearance (such as cloudiness) or a foul smell. Additional symptoms may include back pain and feelings of tiredness or shakiness.

Urinary tract infection (UTI) is usually diagnosed based on symptoms and a positive lab tests, such as urinalysis. Asymptomatic bacteriuria, in which bacteria are present without symptoms, typically does not indicate a UTI and usually requires no treatment, except in pregnant individuals.

Uncomplicated urinary tract infections (UTIs) may resolve without treatment in some people without other health conditions but are often treated with antibiotics like trimethoprim/sulfamethoxazole or fosfomycin, depending on bacterial resistance and individual factors. Complicated UTIs require prompt treatment to prevent kidney damage and the risk of serious infections such as sepsis.

Several supplements, including vitamin C, cranberry, D-mannose, probiotics, and uva ursi, have been studied for the prevention and treatment of urinary tract infections. However, more high-quality studies are needed to confirm their effectiveness.

Diet can affect urinary tract infections (UTIs) by increasing hydration and including foods that acidify urine, which may help prevent recurrent UTIs and aid in resolving uncomplicated cases. Research indicates that increasing daily fluid intake by more than 1 liter may further reduce the risk of UTI recurrence.

Behavioral measures such as increasing hydration and the frequency of urination, as well as modifying personal hygiene, practices, such as proper wiping techniques, can help prevent urinary tract infections (UTIs). In postmenopausal women, vaginal estrogen cream can be used to prevent recurrent UTIs.

Urinary tract infections are primarily caused by bacterial colonization of the urinary tract, which leads to inflammation. Risk factors include sexual activity, certain contraceptive methods, urinary catheters, anatomical abnormalities, and conditions like diabetes and antibiotic use.