Urinary Tract Infection (UTI)

Types of UTI

Doctors also separate uncomplicated UTIs (healthy, non-pregnant women) from complicated UTIs (men, pregnancy, catheters, kidney stones, abnormal urinary tract, weak immunity), which need broader evaluation and longer treatment.

Symptoms

Bladder infection

• burning or stinging when urinating
• a strong, persistent urge to urinate, even right after emptying
• passing small amounts frequently
• suprapubic pain: discomfort, pressure or cramping above the pubic bone
• cloudy, strong-smelling urine
• blood in the urine (pink, red or cola-colored)

Suprapubic discomfort combined with a constant urge to urinate is a classic pattern of a bladder infection, especially with burning.

Kidney infection

• fever and chills
• pain in the back, side or flank, usually on one side
• nausea and vomiting
• bladder symptoms may or may not be present

In older adults and children

Older adults may have few urinary symptoms and instead show confusion, falls, loss of appetite or new incontinence. Babies and young children may have fever, irritability, poor feeding, vomiting or bedwetting.

Causes and risk factors

Most UTIs occur when bacteria from the bowel, usually Escherichia coli, enter the urethra and travel up to the bladder.

• female anatomy: a shorter urethra near the anus
• sexual activity and spermicides
• menopause: low estrogen changes the vaginal bacteria
• pregnancy
• urinary catheters
• urinary retention: enlarged prostate, neurogenic bladder, constipation
• kidney stones and abnormal urinary tract anatomy
• diabetes and weakened immunity
• SGLT2 inhibitor diabetes medicines (small increase in genital infections and UTIs)

Diagnosis

• uncomplicated cystitis in women: often diagnosed from typical symptoms alone, sometimes by telehealth
• urine dipstick: checks for leukocyte esterase and nitrites
• urine culture: identifies the bacteria and the right antibiotic; recommended for men, pregnancy, kidney infection, recurrent UTIs, or when symptoms persist
• blood tests and blood cultures for kidney infection or sepsis
• imaging (ultrasound or CT) for kidney infection that is not improving, recurrent infections, men, or suspected stones or blockage

Asymptomatic bacteriuria (bacteria in urine without symptoms) usually should not be treated, except in pregnancy and before certain urological procedures.

Treatment

Antibiotics

• uncomplicated cystitis: short courses of nitrofurantoin, trimethoprim-sulfamethoxazole or fosfomycin, chosen based on local resistance and allergies
• kidney infection: longer courses of appropriate antibiotics, sometimes intravenous in the hospital
• men and complicated UTIs: longer courses and evaluation for the underlying cause
• pregnancy: pregnancy-safe antibiotics and follow-up culture

Symptoms usually improve within 1 to 2 days. Finish the full course as prescribed.

Symptom relief

• drink plenty of water
• acetaminophen (paracetamol) or ibuprofen at the label dose
• a heating pad on the lower belly
• phenazopyridine (over the counter) can ease burning for up to 2 days; it turns urine orange
• avoid caffeine and alcohol until better

Recurrent UTIs

Recurrent UTI means 2 or more infections in 6 months or 3 in a year. Options include:

• increasing water intake (shown to reduce recurrences in women who drink little)
• vaginal estrogen for postmenopausal women
• methenamine hippurate, a non-antibiotic preventive medicine
• low-dose preventive antibiotics, daily or after sex
• cranberry products may modestly reduce recurrence in some women
• avoiding spermicides

Prevention

• drink enough fluids so urine is pale
• urinate when you feel the urge and after sex
• wipe front to back
• avoid spermicides and harsh feminine products
• treat constipation
• remove urinary catheters as soon as possible

Frequently asked questions

Are suprapubic discomfort and a constant urge to urinate symptoms of a UTI?

Yes. Discomfort or pressure above the pubic bone together with a constant urge to urinate is a typical sign of a bladder infection, especially with burning or frequent small amounts of urine. Other causes include interstitial cystitis and kidney stones, so see a clinician if unsure.

How do I know if my UTI has spread to my kidneys?

Signs of a kidney infection include fever, chills, pain in your back or side under the ribs, nausea and vomiting. These need prompt medical care and usually a longer course of antibiotics.

Can a UTI go away on its own?

Some mild bladder infections in healthy women clear without antibiotics, but many do not, and untreated infections can spread to the kidneys. Antibiotics shorten symptoms and reduce complications. Seek care, especially if symptoms last more than a day or two.

Can men get UTIs?

Yes, though they are less common. UTIs in men are considered complicated and often relate to an enlarged prostate, prostatitis, kidney stones or catheters. Men need a urine culture, a longer antibiotic course and sometimes further tests.

Does cranberry juice cure a UTI?

No. Cranberry does not treat an active UTI. Cranberry products may modestly reduce the risk of recurrent UTIs in some women, but they are not a substitute for antibiotics when you have an infection.