Kidney stones are on the rise. Here’s what you need to know
Kidney stones have become significantly more common, bringing on pain that’s been compared to the pain of childbirth.
Over the last three decades, the prevalence of kidney stones in the United States climbed steadily. In 1994, 5.2% of the population had experienced a kidney stone, and by 2018, the rate was 11%. The number of people who experience kidney stones is nearly as high as the number of people who have diabetes.
What is a kidney stone?
A kidney stone forms from imbalance of promoters and inhibitors in your urine, typically if there’s too much waste and not enough liquid. The small “stone” or “rock” that forms either passes through the urinary tract or gets stuck. And that can lead to intense pain in your lower back and other symptoms including nausea, vomiting, and blood in your urine.
One out of every 9 people will have a kidney stone at some point in their life, and close to 60% of these patients will have recurring stones within 10 years.
What’s causing the increase in kidney stones?
Increased salt and protein consumption and rising prevalence of metabolic syndrome (abdominal obesity, high blood pressure, impaired blood sugar, high cholesterol) have been associated with higher prevalence of kidney stones.
We should be concerned about this rising prevalence of kidney stones. If you form a kidney stone, you have a higher risk of having chronic kidney disease, low bone density, diabetes and slightly higher risk of heart attack and stroke.
Kidney stones cost billions of dollars to treat and result in patients suffering as well as lost productivity. The good news is that most people can significantly cut their risk of having additional kidney stones through specific preventive treatments and lifestyle changes.
How to prevent kidney stones
The internet is full of kidney stone prevention strategies and ideas. Many people have tried online suggestions and found them to be confusing and ineffective.
If you want to prevent a kidney stone, it’s important for doctors to identify your individual risk factors and target treatments to those risk factors, which are different for each patient. The main test to determine your risk for kidney stones is a 24-hour urine test, usually performed by a specialized laboratory. Depending on the specific risk factors identified by the test, common stone prevention treatments include fluid, dietary changes, medications, and lifestyle changes.
The universal recommendation for all patients is to drink more water. You should drink about 100 ounces of water per day, which usually generates about 80 ounces of urine.
How do kidney stones form?
Kidney stones form from minerals in your urine. They’re commonly classified as calcium and non-calcium stones. Most stones contain calcium along with oxalate and phosphate, which are natural compounds found in foods.
Stones form when the urine is concentrated (or supersaturated) with crystals and there’s an imbalance between stone promotors such as calcium, oxalate, uric acid and sodium, and stone inhibitors such as citrate, potassium, and magnesium.
In general, factors that can lead kidney stones include heat and dehydration, diets high in salt, refined sugars and/or protein, and medical conditions such as Crohn’s disease, type 2 diabetes, obesity, thyroid issues, and gout.
Can calcium in your diet affect kidney stones?
A common misconception is that dietary calcium causes calcium stones. In reality, studies have shown that the incidence of kidney stones increases with a low calcium diet. You should maintain normal calcium in your diet — 1,000 to 1,200 mg per day — by eating dairy products including milk, yogurt and cheese, other foods high in Calcium but avoid calcium tablet supplements.
Any recommended dietary changes will be based on the specific risk factors determined by test results.
What are the symptoms of kidney stones?
A kidney stone can cause acute pain in your back and flank area, typically called renal colic. As the stone moves into the lower third of the ureter, it’s typical to experience frequent urination and a constant urge to use the bathroom. The pain can also radiate down into the groin. If the symptoms suddenly resolve, it often means the stone has popped into the bladder.
Other symptoms you might experience include blood in your urine and less severe pain, more like a dull ache that occasionally can be mistaken for chronic back pain.
What to do if you think you have a kidney stone
If you’ve never had a kidney stone before and are in severe pain, the best thing to do is go to an emergency department (ED) and get evaluated. Other conditions such as appendicitis, ectopic pregnancy, aneurysms and more can also cause similar symptoms and need to be ruled out. If a stone is discovered, then the emergency physician can help develop a plan based on the size and location of the stone.
If you have a history of stones, you may be able to judge when you need to go to the ED versus being able to manage the episode at home. If pain lasts more than a day or two, we recommend patients contact our offices, and we can set up further evaluation.
If you develop a fever along with the pain, then this could be a true emergency, and you should always seek to be evaluated in the ED.
Who can diagnose kidney stones?
Many stones are diagnosed initially by emergency physicians, but family physicians and other general practitioners diagnose stones during workups for blood in the urine, recurrent urinary tract infections or back pain. At times, kidney stones are without symptoms and are diagnosed as an incidental finding on X-Ray or CT scan done for other reasons.
To determine the size and location of the stone, a CT scan, ultrasound or X-ray of the abdomen is needed. Stones that are less than 4 to 5 mm in size will typically pass in a few days to a few weeks without surgical intervention. You’ll be treated for pain and encouraged to drink lots of water to help the stone pass. Larger stones — more than 5 to 6 mm — may not pass spontaneously. You may need a referral with a urologist to remove these stones.
How we treat kidney stones
The Metabolic Stone Clinic at The Ohio State University Wexner Medical Center is unique in central Ohio because it offers a multidisciplinary team approach, including care from a nephrologist, urologist and dietitian. A team approach to treatment offers more focus on prevention to reduce your risk for recurrence of kidney stones.
For stones that do not pass on their own, typically following procedures are performed by urologist:
- Shockwave lithotripsy (ESWL)
- Ureteroscopy and laser lithotripsy
- Percutaneous nephrolithotomy (PCNL)
Do kidney stones usually come back?
If you’ve had stones, you’re typically at high risk for getting more stones, especially if you are not on any preventive treatment. Increasing your fluid intake to more than 100 ounces a day can certainly decrease the risk of future stones.
If you’ve had more than one kidney stone, we recommend a formal evaluation with one of the nephrologists with special interest in kidney stones. They will typically have you do 24-hour urine collections that then get analyzed for stone risk factors. Identifying specific risk factors allows targeted treatment to prevent or reduce chances of the next kidney stone.