July 28, 2026
A kidney stone is a mineral deposit that forms within a kidney. If you've ever had one, you probably don't need anyone to remind you how painful it can be. If you haven't, there's a good chance you know someone who has. About 1 in 10 people will develop a kidney stone during their lifetime. But with a little intel, you can reduce your risk for kidney stones and know what to expect if you have one.
"We still don't know all the basic science behind kidney stones," says Julie Riley, MD, an MU Health Care urologist. "But we do know that certain things in your diet and lifestyle can make you more or less prone to develop them."
Dr. Riley shares six interesting facts that everyone should know:
1. The American Diet Creates the Perfect Environment for Kidney Stones
What you eat and drink — or don't drink — can affect your likelihood of developing kidney stones. Dehydration is the No. 1 reason people make kidney stones, and research shows that 75% of Americans may be chronically dehydrated. When you drink more water, it dilutes your urine, making it hard for your body to form kidney stones.
The American diet also tends to be high in salt and reliant on animal protein — both of which increase the risk of kidney stones.
Sodium promotes kidney stones, explains Dr. Riley. High amounts of dietary sodium cause calcium — a key mineral in most kidney stones — to leak from your kidneys into your urine. This can be a setup for making kidney stones.
2. Where You Live Can Affect Your Risk for Kidney Stones
Kidney stones have traditionally been more common in the southern parts of the United States — an area that urologists often refer to as "the stone belt." No one knows for sure why, but experts believe it is related to the hot and humid climate and its effect on hydration.
However, with changes in climate, the stone belt — and an increased incidence of kidney stones — is drifting north. The southern part of Missouri is now considered part of the stone belt.
"With climate change, we have seen an increase in kidney stones throughout the nation," Dr. Riley says. "In the past 30 years, we have more than doubled the rate of kidney stones in the American population. Missouri is expected to be completely encapsulated within the stone belt by 2050."
Other risk factors associated with kidney stones — regardless of your address — include:
- Age, with 30- to 50-year-olds at highest risk
- Genetics, especially in relation to formation of rarer kidney stones
- High blood pressure
- Metabolic syndrome
- Sex, with men more likely to develop kidney stones
3. You Can Have a Kidney Stone and Not Know It
Kidney stones can sit in the kidney without causing pain or symptoms. You may not know you have one until the stone undergoes changes, such as:
- Gets very large and causes a blockage in your kidney
- Moves down through the muscular tube (ureter) that connects the kidney to the bladder
Kidney stones are also often discovered accidentally during unrelated imaging. If you find out that you have a kidney stone, it is important to inform your doctor. Kidney stones do not dissolve on their own — except for uric acid kidney stones, which are uncommon.
"For many of my patients with a kidney stone, we simply monitor the situation," Dr. Riley says. "We often take preventive measures to try to stop the stone from growing or to discourage new stones from growing."
MU Health Care's comprehensive Kidney Stone Program manages kidney stone prevention and maintenance in several ways:
- Laboratory testing, including blood work and urine tests, to understand why you are making kidney stones
- Dietary and medication recommendations to make the kidney environment less friendly to kidney stones
- Medication to ease discomfort and help you pass the stone more easily
"In order for us to figure out why you are making that stone, I need to analyze what's in your urine and blood," Dr. Riley says. "The stone type itself does not provide those answers."
4. Size Doesn't Matter for Kidney Stone Pain
The pain someone feels when passing a kidney stone has nothing to do with pain tolerance or shape of the stone. It also has nothing to do with size. Tiny stones measuring just 2 millimeters (mm) can be excruciating, while a giant stone measuring 2 centimeters may cause very little pain.
"The pain typically has to do with the blockage and swelling the stone causes, and that can be different for each person," Dr. Riley says. She adds that in some cases, the pain level could be related to anatomy if you have small ureters or a lot of scar tissue.
The size of the stone may affect how easily you pass the stone, though. If the stone is less than 6mm, Dr. Riley says you have a 50% chance of passing it on your own. Larger stones are more likely to need surgical intervention.
5. It Can Take 6 Weeks to Pass a Kidney Stone
Whether you pass a kidney stone on your own or need surgery to remove it typically depends on the pain and symptoms you experience and how long the passage is taking.
"If you are able to labor through the pain, we typically give six weeks for you to try to pass the stone on your own at home," Dr. Riley says. After six weeks, a stone can damage the kidney. "However, if you can't tolerate the pain even with medication or you are having severe symptoms, we will step in before that six-week mark and manage it surgically."
Severe symptoms that warrant emergency medical attention include:
- Fever associated with pain
- Intense pain that is new or feels different from what you felt with a previous kidney stone
- Nausea and vomiting
Unfortunately, drinking more fluids will not help push the kidney stone through. However, proven ways to help promote the passage of a kidney stone include:
- Medication that relaxes your muscles to help the stone pass more easily
- Roller coaster rides, especially ones that are rickety and bouncy
- Sexual intercourse
6. Having a Kidney Stone Increases Your Chance of Having More
Kidney stones are considered a chronic disease. According to Dr. Riley, 50% of people who have a kidney stone will have another one within five years. Ten-year risk is even higher — 75%.
"Once your kidney makes a stone, it is likely to make stones again," Dr. Riley says. "Is it genetic? Is it diet? We don't know for sure. But we do know there are ways to reduce your risk of kidney stones."
Lifestyle changes that help reduce the risk of kidney stones include:
- Stay hydrated: Hydration doesn't have to be just about water. Any liquids or foods with high water content can help.
- Eat a heart-healthy diet: Decrease salt intake and go heavy on the vegetables and fruits. Have animal protein in moderation.
- Maintain a healthy weight: Exercise regularly to reduce your risk of metabolic syndrome — a risk factor for kidney stones.
- Consume more citrate: Citrus fruits and citrus-flavored drinks contain citrate, which hinders the formation of kidney stones. Add a slice of lemon, lime or orange to your water to stay hydrated and up your citrate.
- Avoid high doses of vitamins C and D: Taking too much is associated with kidney stones.
- Stop smoking: Smoking has been associated with the formation of kidney stones.
Next Steps and Useful Resources
- Want to discuss more with a doctor? Find a primary care provider or urologist today.
- Had a kidney stone and want to prevent future stones? Learn more about our Kidney Stone Program.
