This is maybe the most common question I get. The answer is far from straight forward and usually a combination of patient-specific factors.
Kidney stones form when, if the urine chemistry is just right, substances combine, crystallize, and then those crystals bind together to form stones.
There are many different types of stones: Calcium Oxalate, Uric Acid, Calcium Phosphate, Magnesium Ammonium Phosphate, and Cystiene stones make up the majority of stone types. About 80-85% of stones are calcium based but it is a common misconception that these calcium-based stones are caused by too much dietary calcium (milk, cheese, yogurt, etc.). Usually it is a problem with the way your body handles the calcium. Abstaining from dietary calcium in these circumstances can do more harm than good.
When looking at ways to prevent stones, I focus on common dietary factors that can increase risk. High sodium intake is probably the biggest contribution to stone risk. Excessive sodium from canned foods, processed meats, restaurants, prepared boxed or frozen meals...all contributes to increased stone risk. I try to get my patients to A) recognize where the sodium in their diet is coming from (rarely just the salt-shaker) and B)keep their sodium intake to <2500mg/day.
Sodium is a big culprit, but chronic dehydration is probably the other most common problem. Stone formers should drink no less than 64oz/day of water, ideally with up to 4oz of lemon juice. Lemon juice is high in citrate which is a potent stone inhibitor. Excessive protein consumption can also lead to a more acidic urine, predisposing to certain types of stones.
If a patient has had more than one stone, or if they are young with a strong family history, I usually recommend blood and 24 hour urine testing for a custom stone prevention workup.
If you or a friend/loved one have lived with recurrent stones and haven't been evaluated for prevention, give us a call.