Kidney Stone Testing

The only way to definitively identify the underlying causes for kidney stones is to perform a 24-hour urine collection analysis. This test ideally should be done after the painful kidney stone attack is over and the patient has resumed his or her usual diet and routine activities.

Performing the test is not difficult, but interpretation of the results can be complicated and many physicians have little or no experience in this type of complex laboratory analysis. If possible, try to find a specialist in kidney stone prevention analysis to help or ask your physician about his or her experience in this particular area. If your urologist is not comfortable analyzing this type of test data, ask for a referral to an expert.

Another problem with 24-hour urine testing is the need for long-term compliance by the patient. Most patients start with the best of intentions, but after 6 months or so many patients have given up on their preventive treatments and go back to their old ways.

In order to prevent as many stones as possible, patients must do the 24-hour urine test so the underlying causes can be identified. Then, they must find a physician skilled in this area and follow his or her advice on a long-term basis, even if they don't think it’s helping. Patients with stones are kidney stone formers for life and if preventive treatment is not continued, more stones will begin to form.

Also, even the very best preventive treatment plan may eventually fail. This is not due to bad science, but is due to the fact that preventing kidney stones is fighting against nature. Successful treatment often means not giving up even if an occasional stone develops.

The five most common findings on 24-hour urine tests are hypercalciuria (high urinary calcium), hyperuricosuria (high urinary uric acid), hyperoxaluria (high urinary oxalate), hypocitraturia (low urinary citrate) and low urinary volume.

Publication Review By: Stephen W. Leslie, M.D., F.A.C.S., Stanley J. Swierzewski, III, M.D.

Published: 10 Jun 1998

Last Modified: 02 Dec 2011