Kidney Stone Education

The Kidney Stone Collaborative, along with our partners, developed the resources below for people suffering from kidney stones. Learn more about kidney stones, treatments, interventions, and preventive strategies. Watch videos from our experts, and look through our library of original published work.

Thanks to our resource and content partners WorstPainEver and Kidneystoners.org

Kidney Stone FAQs

Kidney stones are the formation of crystalline structures in the urinary tract (which includes the kidneys, ureters, and bladder). These stones can cause pain, infection, and kidney damage. Stones can be small, from 1 mm to very large, filling up an entire kidney. For pictures of stones, see our stone gallery.

Stone pain is often described as stabbing and extremely severe. Women commonly say that it is worse than childbirth. The pain can start in the upper back (flank) and then migrate to the abdomen and groin. Changing positions does not help relieve the pain. The pain of a kidney stone is primarily due to blockage of the urine drainage coming down the small tube called the “ureter” that connects a kidney to the bladder.

See a diagram of the urinary system.

It is thought that the increased pressure stretches the kidney and ureter, causing the pain. This is why stone pain can come and go in waves, as the drainage tube is periodically blocked by the stone trying to make its way out. As the stone moves further down the tube, the pain experienced moves down the body. Other symptoms common during a stone episode include seeing blood in the urine, nausea & vomiting, and feeling the urge to urinate. Once a stone is passed and makes it way out of the ureter tube and into the bladder, most patients describe a sensation of instant relief as the blockage and pressure is relieved. However, stones can take from days to weeks to pass.

See a diagram of locations where stones typically get obstructed.

Kidney stones affect 1 out of 10 people during their lifetimes. They are more common than most people realize. There are many factors that determine whether someone will develop a stone with some being under a person’s control while others are out of their hands.

Common factors influencing kidney stone development:

Gender: While men historically have more stones than women, this difference has been getting smaller and smaller and now it is closer to 50/50 than ever before.

Race: Historically it was thought Non-Hispanic whites had most stones, however non Hispanic blacks and Hispanic populations have been shown to make stones as well.

Age: Stones occur most commonly between the 20s to 50s, but data shows children are now making stones more than ever before. 

WATCH:  Dr. David Sas, O.D. explains more about pediatric kidney stones.

Geography: Geographic location may independently contribute to urine composition, through regional diets, sun exposure, and groundwater. Those living in the Southeastern United States appear to be at particular risk of forming stones.

Seasonal Climate: Stone development is more common during the summer months due to dehydration from higher summertime temperatures and possibly also from higher concentrations of calcium in urine resulting from increased sun exposure which can lead to higher levels of Vit D production.

Occupation: Those working in jobs with exposure to climate and dehydration are more prone to stone development.

Body weight: There are higher rates of stones in those with increased weight and body mass index.

Genetics and medical conditions: Conditions like cystinuria, for example, are genetic and can lead to the production of certain types of stones, such as cystine stones. If kidney stones have been a common occurrence in your family, especially from a young age, it might be a hint that genetics are at play. In fact some doctors will offer a genetic screen for certain conditions. Individuals with a history of some conditions, such as medullary sponge kidney or renal tubular acidosis are prone to forming stones. Chronic urinary tract infections can lead to the development of infection related stones, known as struvite stones. Some surgery for weight loss can also lead to more risk of kidney stones.

There are many factors that lead to the development of kidney stones. For details and a visual time-line of the steps in stone formation, see: How do stones form?

The connection between soda and kidney stones is a bit nuanced. Here’s the scoop:

Sodas, especially those that are high in sugar, could contribute to the formation of kidney stones for a few reasons:

Sugar & Fructose: High consumption of sugar, including fructose (which is found in many sodas), can increase the risk of kidney stones. This is because it can increase the amount of calcium, oxalate, and uric acid in your urine, which are key components in many types of kidney stones.

Sodium: Many sodas and other soft drinks also contain sodium (salt), which can increase calcium excretion through urine, potentially contributing to stone formation.

Phosphoric Acid: Some research suggests that colas, in particular, might be linked to stones because they contain phosphoric acid, which could lead to changes in the urine that promote stone formation.

A 2013 study by Curhan et al, showed Participants consuming one or more sugar-sweetened cola servings per day had a 23% higher risk of developing kidney stones compared with those participants consuming less than one serving per week. In that same study, they found that consumption of tea, wine, caffeinated and decaffeinated coffee, water and orange juice was associated with a decreased risk of incident stones.

On the flip side, not all non-cola sodas might have the same effect, and moderate consumption might not significantly increase the risk for everyone. But, it’s all about balance.

Remember, hydration is key for preventing kidney stones, so water is always the best go-to drink. And, squeezing a bit of lemon into your water isn’t just refreshing; it provides citrate, which can help prevent stone formation.

If you’re prone to kidney stones, discussing your diet with your healthcare provider, or dietician can offer personalized advice tailored to your specific health needs. They can help you identify the best dietary choices to prevent kidney stones, considering your overall health and lifestyle.

And lastly, moderation is key! Enjoying a soda occasionally is likely okay for most people, but water should be your main hydration source

Treatment options for stones include allowing a stone to pass by itself, using medications to help pass a stone, and surgery to treat or remove a stone. Read more for more information including videos and diagrams of stone surgeries to help you better understand your options.

Your likelihood of passing a stone will primarily depend on its size, its location, and how long you have been trying to pass a stone.

WATCH:  Dr. Naveen Kachroo explains passing a kidney stone.

A stent is a flexible hollow tube placed inside the ureter. It allows urine to drain around a stone and helps the ureter heal after surgery. It is entirely inside your body and is not visible from the outside. Stents can cause you to feel like you have to urinate often, can cause minor bleeding, and can cause pain. Find out more about stents and watch an expert video here: All about ureteral stents.

Ureteral stents are usually placed in the operating room by your doctor. A flexible wire is slid up the ureter and the stent is slid over the wire. The wire is removed and the stent remains. At each end of the stent are natural “curls” to keep it in place until it is removed or exchanged. See more about stent placement here: How is a ureteral stent placed?

Ureteral stents can be removed in two ways. Most commonly, your doctor will remove the stent by placing a camera into your bladder through your urethra (the tube where urine exits your body). The stent is grasped with an instrument and removed. The second method is used when a string is left attached to the stent. The string, which is visible exiting the urethra, is pulled until the stent comes out. See more about stent removal here: How is a ureteral stent removed?

Some mild amount of discomfort after stent removal is expected.

While most patients experience relief of stent symptoms upon stent removal, some patients (12-20%) experience acute symptoms of renal colic shortly shortly after stent removal.

This is thought to be due to spasms of the ureter or swelling and temporary blockage developing after the stent comes out. The authors of one study showed that a single dose of a non-steroidal anti-inflammatory, like ibuprofen, given 15 minutes before stent removal was highly effective at preventing the severe pain from developing.

Another study recently published in the Journal of Urology by Pearl, showed that an injection of Toradol (a strong anti-inflammatory) before in the office stent removal did not change pain scores but did prevent emergency visits after stent removal.

Knowing the pain is expected can make you more comfortable and rest assured resolution may occur most often between 30 minutes-1 or 2 hours.

READ:  Efficacy of Intramuscular Ketorolac for Preventing Renal Colic Post Stent Removal: Randomized Controlled Trial

A 24-hour urine collection is a lab test that measures what’s in your urine. It is a timed urine collection used in the metabolic evaluation of urinary stone disease.  A 24 hour urine test can identify electrolytes in the urine that can put you at risk for kidney stones. You can read more about this urine test here.

kidney stones

For patients experiencing their first stone episode, the pain can be so severe and sudden that it stops them in their tracks. Without prior knowledge of what a stone episode feels like, it can be confusing and frightening to go through this amount of discomfort, which is usually described as the worst pain someone has ever experienced. A trip to the emergency room is usually required to make the diagnosis and provide treatment for an active kidney stone. X-rays, usually a CT scan, can be used to confirm that a stone is present.

Most doctors feel that kidney stones only cause pain if they are blocking the ureter and trying to pass down towards the bladder. Stones that are not obstructing, such as those located in the kidney’s calyxes, are generally thought to be non-painful. This explains why some patients can have extremely large stones filling up their entire kidney with no or minimal pain.

However, it does appear that some non-obstructing stones can cause pain because of either blockage of small tubular structures in the kidney itself (the collecting tubules) or for other unclear reasons. Supporting this view is a recent medical journal article suggesting that the treatment of small non-obstructing “papillary” stones may provide pain relief. (Gdor et al, Multi-institutional assessment of ureteroscopic laser papillotomy for chronic pain associated with papillary calcifications, J Urol 2011) Additionally, testimonials from many kidney stone patients (including a urologist with a personal history of kidney stones) suggest that some non-obstructing stones can cause pain.

Patients often ask whether something can be taken to dissolve their stones. Unfortunately, the most common stone types (calcium oxalate and calcium phosphate, accounting for 80% of all stones) cannot be dissolved with medications.

However, in patients with uric acid stones, which account for 5-7% of stones, medication to increase your urine pH (potassium citrate, sodium bicarbonate) can sometimes be successfully given to dissolve the stones and prevent them from re-developing. Watch this video by Dr David Goldfarb discuss medications for the treatment of stones.

Diet can play an important role in the prevention of future stones. The three most important dietary factors for most stone formers to modify in reducing their risk of future stones are to increase total fluid intake, decrease salt intake (the major sources of salt are in foods like bread, chips, deli meats, and fast food), and decrease protein (meat) intake, which we define as any food that comes from an animal, including fish, white meat, red meat, chicken. Please see our diet and kidney stone section written by Kristina L. Penniston, PhD.

A 2013 study by Curhan et al, showed Participants consuming one or more sugar-sweetened cola servings per day had a 23% higher risk of developing kidney stones compared with those participants consuming less than one serving per week. In that same study, consumption of tea, wine, caffeinated and decaffeinated coffee, water and orange juice was associated with a decreased risk of incident stones.

The best fluid intake for most is simply water. However if your doctor is recommending alkali (a way to increase your urine pH) We can suggest looking at the following table from the Journal of Urology in 2024. For a more detailed view of this table, you can have a look at the entire article in our published works.

Yes! About 50% of patients will experience another stone. Basic dietary changes can reduce your chances of forming another stone and if prescribed by your physician,  medical treatment can reduce stone events even further. While these changes may not guarantee that you will not form another stone, they can make it less likely that you will have to experience another painful stone episode. Please see below for dietary measures to reduce stone events and please see the section for “medication for kidney stones” for medical prevention.

If you think you are passing a stone, signs indicating that you should seek immediate medical attention include:

  • Fever above 101.5 degrees Fahrenheit
  • Other symptoms of a urinary tract infection with a stone, including burning during urination, cloudy urine, or bad smelling urine
  • Persistent nausea and vomiting
  • Intolerable pain
  • Certain medical conditions can make passing a stone potentially more dangerous, including those with only one kidney, those with diabetes, or those with decreased kidney function

There are three common surgeries for stones. These include ureteroscopy, shockwave lithotripsy, and percutaneous nephrolithotripsy. We go over the pros and cons of each. See below.

6 Basic Dietary Steps to Reduce You Risk for Kidney Stones

To see more in-depth dietary discussion, read the suggestions of Dr. Kristina Penniston

Most kidney stone formers should increase their fluid intake by one liter each day (about 34 oz) above what they normally drink. Make fluidalways available by carrying a water bottle with you. The fluid does not have to be plain water. Try to drink enough to keep your urine clearand colorless.

A high salt intake increases your risk for stones by raising urinary calcium and lowering urinary citrate levels. Both of these things makes it easier for stones to form in your urine. Aim for 2300mg or less of sodium a day.

A high meat intake can cause an increase in urinary uric acid, calcium, oxalate and lower your urine pH. These changes can lead to an increase in stone development. Aim for 6 ounces or less of animal meat a day (including beef, pork, chicken, and seafood).

Eating fruits and vegetables will increase your urinary citrate {an important kidney stone inhibitor} and is also a great alternative way to increase your fluid intake. You can also try drinking orange juice or adding lemon juice to your fluids.

Calcium from dairy or other naturally high calcium foods can reduce your risk of stones. In contrast, calcium supplements (in pill form) may increases your risk of stones and possibly vascular disease as well. Therefore, getting your calcium intake through your diet is preferred unless your doctor or dietician advises you to take calcium supplements for a medical condition.

These include foods such as spinach, rhubarb, chard, beets, nuts, and sweet potatoes. For most patients, a normal amount of these foods is ok. However, for some patients a high oxalate intake increases their risk of stones. Testing by your doctor can help identify whether this applies to you.

Learn More ›

Treatments for Kidney Stones

If you or a loved one have been diagnosed with kidney stones, we understand that you have questions and concerns. One of your main concerns is likely about treatment. Use the following informaton to guide you through treatment options.

Medications for Kidney Stone Prevention

In some patients, the addition of a daily medicine may be recommended by their provider to decrease the risk of future stones. In clinical trials, these medications have been shown to significantly reduce the number of stones events a patient may have.

While many patients are reluctant to take medications and prefer to focus on dietary modification, medications can be a good option, especially in individuals who frequently develop new stones.

Learn More ›

Passing a Stone

There are three main factors that your doctor uses to predict your chances of successful stone passage. These include stone size, stone location, and what length of time you have been trying to pass the stone. Many kidney stones will pass spontaneously and will not require surgical treatment. 

Learn More ›

Surgical Options for Removing Kidney Stones

Understanding what is the best option for treating your kidney stone can be difficult. Lear more as we summarize the benefits and drawbacks of each surgical option. While it still won’t make the decision for you, it can help you to make an informed decision when talking to your urologist.

Learn More ›

Stay Involved

Nearly 10% of the United States population has suffered from stones. You can help connect with our community and support our mission to accelerate kidney stone research.

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