Uric acid stones are a type of kidney stone. Too much uric acid in the body leads to small stones forming, which can cause pain when you pee and blood in the urine. Small uric acid stones may pass on their own. For larger stones, providers may use minimally invasive or noninvasive treatments such as PCNL and shockwave lithotripsy.
Uric acid stones are one of four types of kidney stones. A kidney stone is a collection of minerals and salt that hardens. Kidney stones form in the kidneys or urinary tract, the path that urine takes to leave the body. They can cause pain and blood in the urine, but treatment can help.
Other types of kidney stones include:
Uric acid is a waste product that’s in your blood. Your body produces uric acid when it breaks down chemicals called purines. Most uric acid dissolves in your blood and passes through the kidneys. It leaves your body in your urine.
If you have high levels of uric acid, then crystals start to form. These uric acid crystals combine with other substances in your body and create a solid mass. The mass keeps growing. It may stay in the kidney or move down the urinary tract and settle in the ureter.
If the stones are very small, they may pass out of your body in your urine without too much pain. But if they don’t pass, they cause urine to back up in the kidney, ureter, bladder or urethra. That’s when you get pain and other symptoms.
If you don’t drink enough water, you have a higher chance of developing uric acid stones and other kidney stones. Other risk factors include:
Researchers estimate that one in 10 people in the United States will have a kidney stone at some point in their lives. They’re more common in men than women. For men, the lifetime risk is about 19%. For women, it’s about 9%.
Most people don’t get kidney stones before age 30. But many cases can happen earlier in life, even among children.
Uric acid stones form when:
The main causes of high acidity in urine are:
Other causes of high levels of uric acid include:
Uric acid stones have similar symptoms to other types of kidney stones. The main symptom is pain, which results from irritation or blockages inside the kidneys or urinary tract. You may feel pain in your:
Other symptoms include:
Any type of kidney stone increases your risk of developing kidney disease. If you have a stone, you’re at higher risk of having another one in the next five to seven years.
Your healthcare provider will ask you about your medical history and do a physical exam. Then your provider will do other diagnostic procedures, including:
Small stones (less than 7 millimeters in diameter) may pass on their own. It can take up to three weeks to pass. Even if the stones pass on their own, it’s still important to talk to your provider so you can prevent stones from forming again.
The most important step in uric acid stone treatment is drinking plenty of water to:
Providers recommend that you drink enough to produce about 2.5 liters of urine. To produce that much urine, you need to drink a little more than 2.5 liters of fluid. That’s because you lose fluid through sweating or exercise. Aim for drinking about 3 liters (or about 3.1 quarts) of fluids per day.
Although drinking any fluid counts, it’s best to drink water. Your provider may prescribe medications as well to make the urine less acidic.
Your provider may prescribe medications to:
Alpha blockers are a type of medication that may help stones in the ureter pass faster. Your provider will talk to you about this option if it’s right for you.
You may need surgery if the stones:
Treatment options include minimally invasive or noninvasive techniques:
Your provider will send the stone or pieces of the stone to a lab for analysis.
Drinking a lot of water is one of the best things you can do to reduce the risk of uric acid stones and other kidney stones. Fluids help make your urine less concentrated with waste products. The water helps your body wash away chemicals, so stones don’t form.
You can check the color of your urine to see if you’re drinking enough. Dark-colored pee means you’re not drinking enough. Pee should be light yellow or clear.
Avoid or limit foods high in purines. Too much of this chemical causes your body to produce more uric acid. A high uric acid level leads to more acid in your urine, which results in uric acid stones forming.
To prevent uric acid stones, cut down on high-purine foods, including:
It also helps to limit sugary foods and drinks, especially those that have high-fructose corn syrup. And try to avoid crash diets, which can increase uric acid levels in your blood.
You can take other steps to prevent uric acid stones:
The outlook for uric acid stones and other kidney stones is positive. Many times, stones pass on their own. You may not even need treatment. If you do need treatment, the treatment options are very successful. You’ll likely make a full recovery.
But there is a risk of the stones coming back. Talk to your provider about dietary changes and other steps you can take to prevent another stone.
Call your provider or go to the ER if you think you may have a kidney stone, and you have these symptoms:
If you’ve had a uric acid stone or you’re at high risk for one (or any kidney stone), take steps to stay healthy:
If you have a uric acid stone, ask your provider:
A note from Cleveland Clinic
Uric acid stones are a type of kidney stone. When you have a high level of uric acid in your blood and urine, small stones can form. These stones can block the passage of urine out of your body, causing pain and other symptoms. Many uric acid stones pass on their own. Your provider may prescribe medication to help the stone pass. For larger stones, your provider may recommend noninvasive or minimally invasive procedures. These treatments include shockwave lithotripsy, ureteroscopy and PCNL. Treatments are successful, but uric acid stones may come back. Avoid or limit foods high in purines to reduce your risk. If you have pain in your side, burning when you pee or see blood in your urine, talk to your healthcare provider. The right diagnosis and treatment can help you feel your best.
Last reviewed by a Cleveland Clinic medical professional on 08/19/2021.
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