A kidney stone is a solid mass formed from substances in the urine. These substances are normally passed in your urine, but they can become highly concentrated and crystalize when there is not enough urine volume. This is typically a result of inadequate daily fluid intake. These stone-forming substances are:
These and other chemicals are the “waste products” that must exit the body.
Kidney stones usually range in size from as small as a grain of sand or gravel to the size of a chickpea. They can even be as large as golf balls. Smaller stones (those less than the size of a chickpea) can pass through the urinary tract on their own, but can be associated with significant pain. Depending on their size, you may or may not notice these stones. Larger stones can get trapped in the ureters (tubes which drain the urine from the kidney into the bladder). When this happens, the stones keep urine from exiting the body.
Blocking the flow of urine causes severe pain or bleeding. Stones that can’t pass on their own are treated with surgery. This decision is based on the stone size, number of stones/overall amount, locations, and other factors such as shape, type, and patient preference.
Stones forming in the kidney and traveling down the ureter to the bladder. Sometimes the stone is too large to pass and can block the flow of urine.
The most common type of kidney stone is a calcium oxalate stone. This type of stone happens when calcium and oxalate join in your urine. It can happen when you have high quantities of oxalate, low amounts of calcium and aren’t drinking enough fluids.
Stones caused by uric acid are also fairly common. These come from a natural substance called purine, which is the byproduct of animal proteins (meat, chicken and fish).
These types of kidney stone run in families, so talk to your healthcare provider about your family history.
A kidney stone starts out in your kidney. It can stay there and build up for years. Some people may even have kidney stones in their kidney for long period of time without knowing it’s there. Once it leaves the kidney, the stone travels down the ureters towards the bladder. The kidney stone enters the bladder and then exits the body through the urethra. Small stones pass out of the body with your urine. Larger stones can get stuck along the way out of the body and may need treatment by your healthcare provider.
You can actually have a kidney stone for years without knowing it’s there. Stones can slowly form over years. As long as these stones stay in place within the kidney, you won’t feel anything. Pain from a kidney stone typically starts as the stone moves out of the kidney to pass out of the body. Sometimes, a stone can form more quickly — in a few months. This is related to your risk factors and history of kidney stones. Your healthcare provider will discuss all of your risk factors and might do a 24-hour urine test to check how quickly you develop stones.
Not all kidney stones are made of the same substances. The materials that make up a kidney stone can vary. You could develop a calcium oxalate stone once and then one made of uric acid another time. This change can happen throughout your life and can be due to things like the treatment you were given for your last stone or other medical conditions.
Caucasian men in their 30s and 40s have the highest incidence of kidney stones. However, anyone can develop kidney stones.
Risks for developing kidney stones include:
There are several risk factors for developing kidney stones. These risks can include:
Certain medical conditions can also increase your risk of developing a stone because you have higher or lower levels of the substances that make up a kidney stone. These conditions can include:
There are medications that can increase your risk of developing a stone. These medications can include:
Certain foods can also place you at risk of a kidney stone. These foods include:
You can actually have a kidney stone in your kidney for years and not know it’s there. However, when it starts to move or becomes very large, you may start to feel a few symptoms. Symptoms of a kidney stone can include:
Smaller kidney stones may not cause pain or other symptoms. These small stones pass out of the body in your urine.
Diagnosis of kidney stones starts with a physical exam and review of your medical history. Other tests include:
A CT scan of the abdomen is an imaging test that creates a three-dimensional view of the organs within the abdominal cavity. Typically no contrast (or dye) is used for kidney stone diagnosis.. This test shows the stone size and location and conditions that may have caused the stone to form. In addition, the other organs within this area of the body can be evaluated.
An ultrasound of the urinary tract uses sound waves to detect kidney stones and indirect signs of kidney stones, such as changes in the kidney’s size and shape.
Your treatment options for a kidney stone can vary on the size of the stone and where it is located in your urinary tract. Treatment options include:
No treatment. Sometimes kidney stones can pass through urine on their own depending on the size and location. Drinking plenty of liquids helps the kidney stones travel through the urinary tract. Passing the stone may take up to three weeks.
Medications. Severe pain, requiring an emergency room visit, can be managed with IV narcotics, IV anti-inflammatory drugs, and IV drugs to manage nausea/vomiting. Stones causing less pain can be managed with an anti-inflammatory drug such as ibuprofen. (Caution: Ask your doctor before taking ibuprofen. This drug can increase the risk of kidney failure if taken while having an acute attack of kidney stones – especially in those who have a history of kidney disease and associated illnesses such as diabetes, hypertension and obesity.) Other medications may be given to relax the ureter such as tamsulosin (Flomax®) or nifedipine (Adamant®, Procardia®) so that the stones can pass on their own.
The amount of time it can take to pass a kidney stone varies. A stone that’s smaller than 4 mm may pass within one to two weeks. A stone that’s larger than 4 mm could take about two to three weeks to completely pass.
Though cranberry juice can help prevent urinary tract infections (UTIs), it doesn’t help kidney stones.
Vinegar is acidic and it can sometimes create changes to your urine which helps stones. However, this doesn’t always help. Talk to your healthcare provider about the use of vinegar for kidney stones.
Lemon juice is rich is citrate, which can help prevent kidney stones from forming. Citrates are found in several citrus fruits, including:
There are several ways to decrease your risk of kidney stones, including:
If you develop kidney stones composed of calcium, you may be tempted to cut calcium out of your diet. However, this is actually the opposite of what you should do. If you have calcium oxalate stones, the most common type, it’s recommended that you have a diet higher in calcium and lower in oxalate. Foods that are high in oxalates include:
Foods that are high in calcium include:
It’s also important to drink plenty of fluids to dilute to dilute the substances in your urine.
There are certain foods and drinks might help prevent kidney stones from developing. These can include:
Talk to your healthcare provider about the best foods and drinks to prevent the development of future stones. Often, there will be certain foods that work for you but not for another person.
There are some beverages that aren’t recommended if you have kidney stones, including soda. Sweetened and dark colas are linked to an increased risk of stone formation. You should also avoid drinks with sugar or corn fructose syrup.
However, coffee has been linked to a decreased risk of developing kidney stones. Studies have shown that people who drink coffee have fewer kidney stones.
The outlook for kidney stones is very positive, although this is a risk of recurrence (the stones coming back). Many kidney stones pass on their own over time without needing treatment from your healthcare provider. Medications and surgical treatments to remove larger kidney stones are generally very successful and involve little recovery time.
It is possible to get kidney stones multiple times throughout your life. If you find you keep developing kidney stones, your healthcare provider may work with you to discover why the stones happen. Once the cause is found, you may be able to make lifestyle changes to prevent future stones from forming.
Your risk of injury from a kidney stone can go up based on the size and location of the stone. The size of the stone is important as it passes out of your body. A larger stone could get stuck in your ureter, causing pressure to build up. This can lead to renal failure and, in the worst case (but rare) scenario, you could lose your kidney. The chance of passing a 1 cm stone is less than 10%, and stones larger than 1 cm typically do not pass
Pain from a kidney stone can persist for a few days after completely passing a stone, and this can vary. If the pain persists beyond a week after passing a stone, repeat imaging (typically an ultrasound) is obtained to see if any further blockage is present (sometime due to a remaining stone fragment).
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 04/22/2020