UTI: Reading Your Urine Test Report

Symptoms that suggest a UTI

• Burning sensation or pain while urinating
• Frequent urge to urinate, passing small amounts
• Cloudy, dark or foul-smelling urine
• Pain or pressure in lower abdomen or pelvis
• Blood in urine (pink or red urine)
• Fever, chills and back/flank pain (if infection has reached kidneys)

What the Urine Routine shows in a UTI

What is Urine Culture and why does it matter?

Most common UTI-causing bacteria

• E. coli: 80% of uncomplicated UTIs
• Klebsiella pneumoniae, especially in hospital-acquired UTIs
• Staphylococcus saprophyticus: common in young sexually active women
• Enterococcus: common in elderly men with prostate issues

When is a UTI serious (pyelonephritis)?

Questions to ask your doctor

• Should I wait for the culture result before starting antibiotics?
• Why do I keep getting recurrent UTIs?
• Do I need a kidney ultrasound to rule out stones?
• How much water should I drink daily to prevent recurrence?

Frequently Asked Questions

References

The clinical information on this page is drawn from peer-reviewed sources indexed by the US National Library of Medicine. Links go to the source so you can read it yourself.

1. Acute Pyelonephritis. In: StatPearls. Treasure Island (FL): StatPearls Publishing. NCBI Bookshelf NBK519537

References

Sources cited on this page. PubMed links open the original abstract.

1. Gupta K, Hooton TM, Naber KG, et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women. Clin Infect Dis. 2011;52(5):e103–e120. PMID 21292654 · doi:10.1093/cid/ciq257

Uncomplicated versus complicated UTI – why the distinction changes management

A urinary tract infection is classified as uncomplicated or complicated, and this distinction fundamentally changes investigation and treatment:

• Uncomplicated UTI: Lower tract infection (cystitis – bladder) in a non-pregnant adult woman with no structural or functional abnormality of the urinary tract, no immunosuppression, and no recent hospitalisation. This accounts for approximately 80% of UTIs. Diagnosed and treated empirically on clinical grounds – a urine culture is not mandatory in straightforward cases, and a 3–5 day course of nitrofurantoin or trimethoprim is curative in most.
• Complicated UTI: Any of the following: upper tract infection (pyelonephritis – kidney), UTI in a man, a pregnant woman, a child, or an older person with functional decline; structural abnormality (kidney stones, ureteric obstruction, neurogenic bladder); catheter-associated UTI; immunosuppression; recurrent infections (3 or more per year). These require urine culture and sensitivity testing before and alongside treatment, longer antibiotic courses, and sometimes imaging.

Urine dipstick – what each result means

The urine dipstick is the primary point-of-care UTI test. Understanding each reagent strip:

• Nitrites: Gram-negative bacteria (E. coli, Klebsiella, Proteus) convert urinary nitrates to nitrites. A positive nitrite strongly supports bacterial UTI – but false negatives occur with dilute urine (the dipstick needs adequate time for the conversion, typically 4 hours of urine in the bladder), Gram-positive organisms (Enterococcus, Staphylococcus – do not produce nitrites), and high vitamin C intake.
• Leucocyte esterase: Enzyme released by white blood cells (WBCs). Positive = pyuria (white cells in urine), suggesting infection or inflammation. Pyuria without bacteriuria occurs in TB of the urinary tract (sterile pyuria – the classic finding), interstitial nephritis, and contamination.
• Combined result interpretation: Nitrites positive + leucocyte esterase positive = treat empirically for UTI (high positive predictive value). Both negative = UTI unlikely (high negative predictive value). Discordant results (one positive, one negative) require clinical judgement and potentially a mid-stream urine (MSU) culture.

Recurrent UTI – investigating the underlying cause

Three or more culture-confirmed UTIs per year (or two in 6 months) warrant investigation to exclude a structural, functional, or hormonal cause:

• Renal tract ultrasound: Identifies stones, obstruction, residual urine (post-void residual), or structural abnormality
• Post-void residual measurement: Incomplete bladder emptying (above 50–100 mL residual) perpetuates infection by preventing mechanical clearance of bacteria
• Cystoscopy: Identifies bladder lesions, fistulae, or stones not seen on ultrasound
• Oestrogen deficiency (in postmenopausal women): Atrophic vaginal and urethral epithelium is more susceptible to colonisation. Local vaginal oestrogen significantly reduces recurrent UTI frequency in this group – by approximately 50% in trials.