What Are Kidney Stones?
Kidney stones are becoming more common in the U.S. According to the National Kidney Foundation, 1 in 11 people get kidney stones each year. But in 1994 that rate was only 1 in 20.
Kidney stones form when minerals in urine create crystals. These crystals can grow large enough to block the ureters (tubes that carry urine). This can stop urine flow and affect kidney function. Symptoms include:
- Severe pain in the abdomen or lower back
- Nausea and vomiting
- Fever
- Frequent, painful urination
- Blood in the urine
"If you have a fever, blood in your urine or uncontrolled pain, it's important to seek medical care," says Jill Bloom, PA, Carilion Clinic Urology. "You may need to have your urine checked, and possibly blood work and imaging of your urinary tract. Certain medication may help pass some stones."
Sometimes, kidney stones are caused by genetic disorders or kidney infections. But most stones are calcium-oxalate or uric acid stones, which come from minerals in our diet.
So How Do You Avoid Them?
Jill suggests these tips to help prevent kidney stones:
1. Hydrate
Sweating from exercise or heat reduces urine production. Less urine means more minerals can settle and form stones. Drink plenty of water to urinate often. Urine should be clear to pale yellow. If you’re prone to kidney stones, your urine output should be between 2.5 to 3.0 liters per day.
2. Be Mindful of Minerals
Calcium-oxalate stones are the most common. Oxalate is found in fruits, vegetables, nuts, seeds, grains, legumes, chocolate and tea. Consume calcium along with these foods so the minerals bind in the stomach and intestines, not in the kidneys.
3. Spare the Salt
Sodium makes the kidneys pass more calcium into urine. The average American eats almost double the recommended 2,300 mg of sodium each day. Limit sodium to the recommended amount to help prevent stones.
4. Switch From Sweet to Tart
Potassium citrate prevents calcium from crystallizing. Lemonade, limeade, and other tart fruits high in natural citrate offer similar benefits. Enjoy fresh lemonade, but limit sugar and high fructose corn syrup, which can increase kidney stone risk.
5. Avoid Purine
Purine is found naturally in foods like red meat, shrimp and shellfish. Too much of this chemical causes uric acid stones. Eating less animal protein and more fruits and vegetables can lower urine acidity and reduce stone formation. Be sure to limit alcohol intake too.
Small Changes Make a Big Difference
Jill notes that people who have had stones have a 90% chance of getting another within 10 years without dietary or lifestyle changes. If there are no metabolic issues, which can be treated with medication, these changes are crucial to prevent recurrence.
"Increase your urine output to over 2.5 liters per day. You should also reduce oxalates, monitor sodium and protein intake and maintain a healthy weight. All these things can decrease your risk," she says. So drink up, watch your diet and stay active. Your kidneys will thank you!
If you think you have kidney stones, call your doctor. Early intervention can prevent complications and make treatment more effective.
