At-home bladder infection tests: reading the result

Most kits are dipsticks that change colour in response to nitrites and white-blood-cell enzymes. These findings may support suspicion of a urinary infection, yet neither a positive nor a negative strip settles the diagnosis. A laboratory urine test may be needed to identify bacteria and guide treatment.

Nitrites can appear when certain urinary bacteria convert naturally occurring nitrate. A leukocyte result suggests white blood cells are present, which can occur with inflammation or contamination as well as infection. Blood on a strip has several possible causes and deserves clinical interpretation if it persists.

A negative strip does not exclude infection because not every bacterium produces nitrites and urine may not have remained in the bladder long enough for nitrites to develop. Menstrual blood, vaginal discharge, an old strip, incorrect timing and a poorly collected sample can alter the reading.

Follow the kit instructions exactly, check the expiry date and compare colours at the stated time. If collecting urine, wash your hands and use a clean midstream sample where possible. Record burning, urgency, frequency, lower abdominal discomfort, urine appearance, fever and back or side pain.

Contact a clinician if urinary symptoms are troublesome, recurring or not improving, regardless of the strip result. Assessment is especially useful during pregnancy, for children, for men, or when kidney disease, urinary abnormalities or reduced immunity are present. Do not use leftover antibiotics or another person's medicine.

Seek same-day medical care for fever, chills, vomiting, pain in the back or side below the ribs, visible blood in urine, inability to pass urine, or feeling markedly unwell. A kidney infection can present with urinary symptoms alongside fever, chills, nausea or flank pain.

Call emergency services for confusion, severe drowsiness, collapse, difficulty breathing, mottled skin or rapid deterioration. These warning signs can occur with sepsis and should never be managed by repeating a home dipstick.

Ask whether you need urine microscopy or culture, how and when to provide the sample, what else could explain the symptoms, and which changes should trigger urgent reassessment. If infections recur, ask whether bladder habits, stones, prostate problems or another urinary condition need evaluation.