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Tests & diagnostics

Kidney stone metabolic workup

The metabolic work-up after kidney stones - blood tests, 24-hour urine analysis and stone analysis to stop the next stone forming.

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At a glance

  • Preparation

    Save any stone you pass in a clean container for laboratory analysis, and complete the 24-hour urine collection on days reflecting your normal diet and fluids.

  • What happens during the test

    The work-up combines blood tests - calcium, urate, kidney function, parathyroid hormone - with one or two 24-hour urine collections measuring the chemistry that drives stone formation.

  • Results timeline

    Blood results return within days; 24-hour urine panels typically report within one to two weeks.

  • Specialist follow-up

    A urologist or metabolic specialist converts the results into a personal prevention plan of fluid targets, dietary adjustment and, where indicated, medication.

What this test is and when it is recommended

Around half of people who form one kidney stone will form another within ten years - unless the cause is found and corrected. The metabolic work-up is how that happens: stone analysis identifies the type, blood tests screen for drivers such as hyperparathyroidism and gout, and the 24-hour urine reveals the individual chemistry - low volume, high calcium, high oxalate, low citrate - fuelling recurrence. Prevention that follows is mundane but powerful: fluid intake to produce two and a half litres of urine daily, adjusted rather than restricted calcium, less salt, and targeted medication.

How to access it

A recurrence work-up is arranged through a urologist via GP referral or a directly booked private stone clinic appointment. NHS diagnostic queues can stretch to months in many areas, whereas private clinics can generally see you within days to about two weeks.

Frequently asked

Common questions about Kidney stone metabolic workup.

Quick, plain-English answers to what people ask us most.

  • What is a kidney stone metabolic workup?

    This is a set of blood and urine tests, sometimes including a 24-hour urine collection, used to identify the underlying metabolic factors that may be contributing to kidney stone formation, such as calcium, oxalate, citrate or uric acid levels.

  • Why would a doctor order this workup?

    It's typically recommended after someone has had one or more kidney stones, particularly if stones recur, to identify modifiable risk factors and guide prevention strategies such as dietary changes or medication.

  • Do I need to prepare for this workup?

    You'll usually be asked to eat your normal diet in the days before testing, as changing your habits beforehand can affect the accuracy of the results, and specific instructions will be given for any 24-hour urine collection.

  • What happens during the workup?

    It generally involves blood tests plus one or more urine collections, sometimes over a full 24-hour period, to capture a representative picture of your body's handling of stone-forming substances over a typical day.

  • Does it carry any risks?

    There's minimal risk involved, similar to any blood test, and the urine collection itself is non-invasive, though it does require careful, consistent collection to be accurate.

  • How long do results take?

    Results are typically available within one to two weeks, since a detailed metabolic panel and 24-hour urine analysis take longer to process than routine blood tests.

  • What do abnormal results mean, and what happens next?

    Specific abnormalities, such as high urine calcium or low citrate, point towards particular dietary or medical strategies to reduce future stone risk, which your doctor or urologist will discuss with you in detail. The goal is usually prevention of further stones rather than treating an existing one, which is managed separately if still present.

  • Is this workup available on the NHS, and how much does private testing cost?

    It's available through NHS urology or renal stone clinics, particularly after recurrent stones, though referral and waiting times can vary. Private clinics typically offer this within one to two weeks, with cost varying by provider.

  • How reliable is a metabolic stone workup?

    It's a well-established approach for identifying modifiable stone risk factors, though accuracy depends on collecting samples correctly and on your diet being reasonably typical during testing, so following instructions carefully matters.

  • How do I book this workup privately?

    You can book a consultation with a private urologist or renal specialist, who will arrange the appropriate tests, typically with results available within about two weeks.