The phrase “passing a kidney stone” may make you cringe a little, even if you don’t have any experience with this agonizing process.
Kidney stones are a high concentration of stone-forming minerals that develop in the urine. These minerals form together to create hard crystal deposits that are often painful as they pass through the urinary tract. If you have a kidney stone, you may experience severe pain in your back or side and nausea.
According to research published by the National Institutes of Health, kidney stones affect approximately 5 percent of adults in the U.S., with men slightly more likely than women to develop the condition. The article also reported that those who’ve had kidney stones before are much more likely to develop them again.
“We typically don’t see kidney stones in people under the age of 30 unless there is an underlying disease causing the stones,” said Anthony De Mory, MD, of Samaritan Kidney Specialists. “However studies show that stones occur more often now than they did 30 years ago, which we think is due to an overall increase in body weight.”
There are several different types of kidney stones, but by far the most common, making up 70 to 80 percent of cases, are stones with deposits of calcium oxalate, phosphate or both. Other kidney stone types include uric acid, struvite, cystine, and a very small number of other, more rare deposits.
“Kidney stones are just an excess of a certain mineral in comparison to the rest of the urine,” said De Mory. “Determining what kind of kidney stone you have can help you determine how to prevent them in the future, but given the large prevalence for calcium oxalate stones there are a few things that the general population can do to reduce their risk.”
Although the most common reason for kidney stones is a variety of metabolic disorders that lead the body to excrete more calcium than average, diet can also contribute to the formation — and prevention — of stones.
De Mory recommends:
- Get the recommended amount of calcium and vitamin D. In studies, too little calcium in the diet could lead to calcium oxalate stones, but calcium supplements that included vitamin D could also lead to stone formation.
- Don’t overdo the protein, sodium or sugar. Diets high in these substances are associated with a higher risk for recurring kidney stones.
- Drink enough water. You should drink enough water that your urine output is two liters a day, or about 8 cups. For the most part, fluid in equals fluid out so make regular water breaks a habit. However if you have a health condition like heart or liver disease, or some other kidney problem, always follow your doctor’s advice about fluid intake.
- Talk to your doctor if you have a family history. It’s not something you can control like diet, but if others in your family have a history of kidney stones, you may be at greater risk. Your doctor may recommend a blood or urine test, which can help give specific guidance about the best preventive measures for you.
De Mory acknowledges that there are still many unknown factors around what causes kidney stones. Although it is true that high concentrations of certain minerals lead to stone formations, not everyone with high concentrations has kidney stones.
“Based on what we know, a balanced diet, fluids, and awareness of a familial tendency toward kidney stones is the best way to lower your risk,” he said.
Learn more about kidney stones in our health library.