Kidney stones also referred to as renal calculi, are small masses of crystallized minerals and salts that develop inside the kidneys. Kidney stones form when urine has a higher concentration of substances— such as calcium, oxalate, and uric acid—than it can dissolve.
Kidney stones usually have no single cause, but they have various contributing factors, such as dehydration, certain diets (e.g., high-sodium diet), obesity, and family or personal history.
If you’ve already had kidney stones, you have a higher risk of developing them again. It greatly helps to consult a nephrologist (kidney doctor), even before you manifest the subtlest signs of the problem. Your kidney doctor will employ a combination of preventive medications and dietary recommendations, as explained below.
There are four different types of kidney stones: calcium oxalate, calcium phosphate, uric acid, and cystine. The type of preventive medication your kidney doctor will prescribe will depend on the type of kidney stones you are prone to having. For instance, if you are prone to getting calcium oxalate stones (the most common type of kidney stones), your kidney doctor will prescribe a thiazide diuretic, which can reduce the amount of calcium released into your urine. Or, if you are prone to having uric acid stones, your kidney doctor will prescribe allopurinol to lower your uric acid levels.
Dietary and Fluid Intake Recommendations for Kidney Stones
To reduce your risk of recurrent kidney stones, your doctor will make specific dietary and fluid intake recommendations, such as:
- Increasing Your Water Intake
Drinking enough water is the mainstay of strategy for preventing the recurrence of kidney stones, regardless of the type. Staying well hydrated ensures increased urine production. Nonetheless, there’s no hard-and-fast rule as to how many glasses of water you should consume. The eight-glasses-of-water-a-day advice is just a general recommendation.
A good rule of thumb is to monitor the color of your urine. If it has a pale yellow or close-to-clear color, it means that you’re adequately hydrated.
If you live in a place where the climate is hot or if you regularly engage in strenuous activities, your kidney doctor will likely recommend that you drink more than eight glasses of water a day to prevent dehydration.
- Lowering Your Salt Intake
Eating foods high in salt can trigger kidney stones, as it increases the amount of calcium in your urine. Current guidelines emphasize the importance of reducing your daily sodium intake to less than 2,300 mg—that’s equal to approximately 1 teaspoon of table salt.
- Limiting Consumption of Foods High in Oxalate (if You’re Prone to Calcium Oxalate Stones)
If you’re prone to calcium oxalate stones, your kidney doctor will advise against eating peanuts, rhubarb, spinach, beets, Swiss chard, chocolate, and sweet potatoes as these foods are loaded with oxalates. When your oxalate levels are high, the excess oxalate binds with calcium to form kidney stones.
- Avoiding High-Purine Foods (if You’re Prone to Uric Acid Stones)
If you’ve had uric acid stones, your kidney doctor will have you avoid eating red meat, organ meats, and shellfish, as these have high amounts of a natural chemical compound known as purines.
High purine intake results in increased production of uric acid and a larger acid load for your kidneys to excrete. Higher uric acid excretion leads to more acidic urine. The high acid concentration in your urine makes it conducive to uric acid stone formation.
- Exercising Caution When Using Calcium Supplements
Calcium in itself is not a culprit in kidney stone formation. In fact, your doctor will likely even recommend that you incorporate it into your diet—as long as you obtain it from natural food sources.
Studies suggest that large doses of supplemental calcium, especially when taken separately from meals, may contribute to kidney stone formation. If you’re not getting enough calcium from your normal diet, your doctor may allow you to take calcium supplements, but you do have to make sure to do it with meals.
Kidney Doctor in Marlborough, MA
At Commonwealth Nephrology Associates, our board-certified kidney doctors pride themselves on their unwavering commitment to providing high-quality, comprehensive care and delight in educating our patients about the importance of being proactive about their health.
To learn more about kidney stone prevention or if you have other concerns about your renal health, call us at (617) 739-2100 to schedule a consultation with one of our kidney doctors. You can also use our convenient online form.
We have offices in Norfolk, Natick, Marlborough, South Weymouth, Dorchester, Westboro, and Attleboro.