White kidney stones: what to know

A kidney stone is a hard collection of crystals that forms in the urinary tract. Stones differ in size, texture, and colour, ranging from pale or white to yellow, brown, or darker shades. A stone’s appearance alone cannot reliably show its chemical makeup or explain why it formed.

Stones may cause sudden pain in the side or back that moves toward the lower abdomen or groin. Other possible features include nausea, blood in urine, painful urination, urgency, or difficulty passing urine. Some stones cause little or no discomfort until they move or obstruct urine flow.

If you can collect a passed stone without delaying care, place it in a clean dry container and take it to your appointment. Analysis can help guide prevention advice. Drink fluid according to your usual health advice; do not force large amounts if you are vomiting, unable to pass urine, or have been told to limit fluids for another condition.

A clinician may assess urine, pain, hydration, and whether imaging is needed to look for a stone or blockage. An abdominal ultrasound is one way to investigate some urinary tract problems. Take only pain relief that is safe for you, following the label or advice from a clinician or pharmacist.

Seek urgent medical care for fever or chills with urinary pain, persistent vomiting, severe pain that is not controlled, inability to pass urine, confusion, or feeling very unwell. Infection together with an obstructed urinary tract can become serious and needs prompt treatment.

Arrange a GP consultation for repeated flank pain, blood in the urine, ongoing painful urination, or a suspected stone that has not been assessed.

Ask whether a stone analysis or urine testing is useful, whether imaging is needed, and what prevention plan fits your health history. Mention previous stones, bowel disease or surgery, family history, supplements, and medicines, because these details can affect the next steps.