Urine test for kidney stones: what it can show

A urine sample may show red blood cells, crystals, protein, white blood cells, bacteria, or concentrated urine. These findings can support a kidney-stone assessment and may suggest irritation or infection, but a normal sample does not exclude a stone. Different stone types can produce different crystal patterns, and crystals may appear without a stone.

The clinician combines the report with the pattern of pain, examination, kidney function, and your history. An [Abdominal Ultrasound](/treatments/diagnostics-and-screening/abdominal-ultrasound/) may help look for obstruction or swelling, while a [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can coordinate the assessment.

Collect the sample exactly as instructed and tell the clinician about previous stones, fluid loss, medicines, pregnancy possibility, and recent changes in urination. Do not add water to the specimen. Drinking fluids may be appropriate for some people, but do not force fluids if you are vomiting, have severe pain, or have been given a fluid restriction.

Follow the treatment plan rather than trying to diagnose the stone from colour or crystals alone. If you pass a stone, ask whether it should be saved for analysis. Review [Kidney Stones](/conditions/kidney-stones/) for broader information.

Seek urgent medical help for severe or escalating flank or abdominal pain, fever or chills with urinary symptoms, repeated vomiting, or inability to keep fluids down. Infection behind an obstruction can become serious and needs prompt assessment.

Get urgent care if you cannot pass urine, have heavy visible blood, fainting, or marked weakness. Painful urination, [Flank Pain](/symptoms/flank-pain/), [Abdominal Pain](/symptoms/abdominal-pain/), or [Difficulty Passing Urine](/symptoms/difficulty-passing-urine/) should be assessed, particularly when symptoms are new or worsening.

What did the urine sample show? Could infection or obstruction be present? Do I need ultrasound or another scan? How should I manage fluids and pain? Should a passed stone be analysed?