Tuesday, September 2, 2014
Kidney Stones and Calcium Levels
I have had many kidney stones in the past five years. Mine all seem to be calcium. I have done the 24hr urine test ....the one where you collect your urine for a day. My doctor found that I had really high amounts of calcium in my urine. He put me on Hydrochlorothiazide. He says that medicine keeps the calcium in the intestines. The meds seem to be working....I haven`t made any new stones. My question is what is it that makes me have so much calcium in my urine? Should he do any further test to see what is cause too much calcium ....now that he found what is causing the stones?
There are different causes for high calcium in the urine (hypercalcuria) such as absorptive (Type I, II, III), Renal leak and resorptive hypercalciuria. There are various tests that can be done to differentiate between these subtypes but are not routinely done in a clinical setting. Resorptive hypercalciuria is usually due to hyperparathyroidism (elavated serum calcium and elevated parathyroid hormone) and is treated differently than with Thiazides. Type III absorptive is suspected in patients with low blood phosphate levels and increased urine phosphate levels and might require to be treated differently than the other hypercalciurias which respond to Thiazides/dietary modifications.
You can discuss these issues further with your urologist; usually most of these levels are part of the 24 hour urine workup, which you have had done. The fact that you seem to be responding to the hydrochlothiazide is encouraging, as recurrent kidney stone disease can be a difficult problem to treat.
Krishnanath Gaitonde, MD
Assistant Professor of Clinical Urology
College of Medicine
University of Cincinnati