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Cystinuria

Show Alternative Names
Stones - cystine
Cystine stones

Cystinuria is a rare condition in which stones made from an amino acid called cysteine form in the kidney, ureter, or bladder. Cystine is formed when two molecules of an amino acid called cysteine are bound together. The condition is passed down through families.

Video Transcript

Kidney stones - Animation

If you ever have severe pain in your belly or one side of your back that comes and goes suddenly, you may be passing a kidney stone. Let's talk about the painful condition of kidney stones. A kidney stone is a mass of tiny crystals in your kidney or urinary tract. Stones are quite common, and tend to run in families. They can form in weeks or months when your urine contains too much of certain substances. There are several kinds of kidney stones. Calcium stones are by far the most common kind. They often form in men between the ages of 20 to 30. Calcium can combine with other substances found in your food, like oxalate, phosphate, or carbonate, to form stones. Cystine stones can form in people who have cystinuria, a condition passed down through families in which stones are made from an amino acid called cystine. Struvite stones are found mostly in women who have urinary tract infections. These stones can grow very large and can block the kidney, ureter, or bladder. Uric acid stones are more common in men than in women. They can occur in people who have a history of gout or are going through chemotherapy. So, how do you know if you have kidney stones? Well, you may not have symptoms until the stone move down the ureter tubes through which urine empties into your bladder. When this happens, the stones can block the flow of urine out of your kidneys. The main symptom is severe sharp pain that starts suddenly, usually in your belly or one side of your back, and it may go away just as quickly. Other symptoms can include abnormal urine color, blood in your urine, fever, chills, nausea, and vomiting. So, what do you do about kidney stones? Well, your health care provider will perform a physical exam. You may need blood tests, kidney function tests, and tests that look for crystals in your urine. Several imaging tests, like a CT scan, can see stones or a blockage in your urinary tract. Treatment will depend on the type of stone you have, and how bad your symptoms are. Small kidney stones that are less than 5 mm in diameter will usually pass on their own. You should drink at least 6 to 8 glasses of water per day to produce a large enough amount of urine to help bring the stone out. Pain can be pretty bad when you pass a kidney stone, so your doctor may prescribe pain medicines to help as well as medications that will help the stone pass. Other medicines can decrease stone formation or help break down and remove the material that is causing you to make stones. You may need surgery if the stone is too large to pass, the stone is growing, or the stone is blocking your urine flow. Kidney stones are painful, but you can usually pass them without causing permanent harm. However, kidney stones often come back, so you and your doctor will need to work on finding the cause of your stone. Lastly, delaying treatment can lead to serious complications, so if you think that you have kidney stones see your doctor right away.

Causes

To have the symptoms of cystinuria, you must inherit a variant gene from both parents. Your children will also inherit a copy of the variant gene from you.

Cystinuria is caused by too much cystine in the urine. Normally, most cystine dissolves and returns to the bloodstream after entering the kidneys. People with cystinuria have a genetic change that interferes with this process. As a result, cystine builds up in the urine and forms crystals or stones. These crystals may get stuck in the kidneys, ureters, or bladder.

About one in every 7000 people have cystinuria. Cystine stones are most common in young adults under age 40. Less than 3% of urinary tract stones are cystine stones.

Symptoms

Symptoms include:

  • Blood in the urine
  • Flank pain or pain in the side or back. Pain is most often on one side. It is rarely felt on both sides. Pain is often severe. It may get worse over days. You may also feel pain in the pelvis, groin, genitals, or between the upper abdomen and back.

Exams and Tests

The condition is most often diagnosed after an episode of kidney stones. Testing the stones after they are removed shows that they are made of cystine.

Unlike calcium-containing stones, cystine stones do not show up well on plain x-rays.

Tests that may be done to detect these stones and diagnose the condition include:

Treatment

The goal of treatment is to relieve symptoms and prevent more stones from forming. A person with severe symptoms may need to go into the hospital.

Treatment involves drinking plenty of fluids, especially water, to produce large amounts of urine. You should drink at least 6 to 8 glasses per day. You should drink water at night as well so that you get up at night at least once to pass urine.

In some cases, fluids may need to be given through a vein (by IV).

Making the urine more alkaline may help dissolve the cystine crystals. This may be done with use of potassium citrate or sodium bicarbonate. Eating less salt can also decrease cystine release and stone formation.

You may need pain relievers to control pain in the kidney or bladder area when you pass stones. Smaller stones (5 mm or less in diameter) most often pass through the urine on their own. Larger stones (more than 5 mm) may need extra treatments. Some large stones may need to be removed using procedures such as:

  • Extracorporeal shock wave lithotripsy (ESWL): Sound waves are passed through the body and are focused on the stones to break them into small, passable fragments. ESWL may not work well for cystine stones because they are very hard as compared with other types of stones.
  • Percutaneous nephrostolithotomy or nephrolithotomy: A small tube is placed through the flank directly into the kidney. A telescope is then passed through the tube to fragment the stone under direct vision.
  • Ureteroscopy and laser lithotripsy: The laser is used to break up the stones and can be used to treat stones that are not too large.

Outlook (Prognosis)

Cystinuria is a chronic, lifelong condition. Without treatment, stones commonly return. However, the condition rarely results in kidney failure. It does not affect other organs.

Possible Complications

Complications may include:

When to Contact a Medical Professional

Contact your health care provider if you have symptoms of urinary tract stones.

Prevention

There are medicines that can be taken so cystine in the urine does not form a stone. Ask your provider about these medicines and their side effects.

Any person with a known history of stones in the urinary tract should drink plenty of fluids to regularly produce a high amount of urine. This allows stones and crystals to leave the body before they become large enough to cause symptoms. Decreasing your intake of salt or sodium will help as well.

Review Date: 3/31/2024

Reviewed By

Sovrin M. Shah, MD, Associate Professor, Department of Urology, The Icahn School of Medicine at Mount Sinai, New York, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

References

Di Carlo HN, Crigger CB . Urinary lithiasis. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 584.

Guay-Woodford LM. Hereditary nephropathies and developmental renal/urinary abnormalities. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 113.

Miller NL, Borofsky MS. Evaluation and medical management of urinary lithiasis. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 92.

Sakhaee K, Moe OW. Urolithiasis. In: Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector's The Kidney. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 38.

Disclaimer

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

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Kidney stones

Kidney stones

Animation

Female urinary tract - Illustration Thumbnail

Female urinary tract

The female and male urinary tracts are relatively the same except for the length of the urethra.

Illustration

Male urinary tract - Illustration Thumbnail

Male urinary tract

The male and female urinary tracts are relatively the same except for the length of the urethra.

Illustration

Cystinuria - Illustration Thumbnail

Cystinuria

Cystinuria is a disorder characterized by cystine stones in the kidney, ureter, and bladder. A genetic abnormality results in abnormal transport of amino acids in the kidney. The high levels of the amino acid cystine in the urine lead to stone formation.

Illustration

Nephrolithiasis - Illustration Thumbnail

Nephrolithiasis

Kidney stones result when urine becomes too concentrated and substances in the urine crystalize to form stones. Symptoms arise when the stones begin to move down the ureter causing intense pain. Kidney stones may form in the pelvis or calyces of the kidney or in the ureter.

Illustration

 
Kidney stones

Kidney stones

Animation

 
Female urinary tract - Illustration Thumbnail

Female urinary tract

The female and male urinary tracts are relatively the same except for the length of the urethra.

Illustration

Male urinary tract - Illustration Thumbnail

Male urinary tract

The male and female urinary tracts are relatively the same except for the length of the urethra.

Illustration

Cystinuria - Illustration Thumbnail

Cystinuria

Cystinuria is a disorder characterized by cystine stones in the kidney, ureter, and bladder. A genetic abnormality results in abnormal transport of amino acids in the kidney. The high levels of the amino acid cystine in the urine lead to stone formation.

Illustration

Nephrolithiasis - Illustration Thumbnail

Nephrolithiasis

Kidney stones result when urine becomes too concentrated and substances in the urine crystalize to form stones. Symptoms arise when the stones begin to move down the ureter causing intense pain. Kidney stones may form in the pelvis or calyces of the kidney or in the ureter.

Illustration

 
 
 

Kidney stones - Animation

If you ever have severe pain in your belly or one side of your back that comes and goes suddenly, you may be passing a kidney stone. Let's talk about the painful condition of kidney stones.

A kidney stone is a mass of tiny crystals in your kidney or urinary tract. Stones are quite common, and tend to run in families. They can form in weeks or months when your urine contains too much of certain substances.

There are several kinds of kidney stones. Calcium stones are by far the most common kind. They often form in men between the ages of 20 to 30. Calcium can combine with other substances found in your food, like oxalate, phosphate, or carbonate, to form stones.

Cystine stones can form in people who have cystinuria, a condition passed down through families in which stones are made from an amino acid called cystine. Struvite stones are found mostly in women who have urinary tract infections. These stones can grow very large and can block the kidney, ureter, or bladder. Uric acid stones are more common in men than in women. They can occur in people who have a history of gout or are going through chemotherapy.

So, how do you know if you have kidney stones?

Well, you may not have symptoms until the stone move down the ureter tubes through which urine empties into your bladder. When this happens, the stones can block the flow of urine out of your kidneys. The main symptom is severe sharp pain that starts suddenly, usually in your belly or one side of your back, and it may go away just as quickly. Other symptoms can include abnormal urine color, blood in your urine, fever, chills, nausea, and vomiting.

So, what do you do about kidney stones?

Well, your health care provider will perform a physical exam. You may need blood tests, kidney function tests, and tests that look for crystals in your urine. Several imaging tests, like a CT scan, can see stones or a blockage in your urinary tract.

Treatment will depend on the type of stone you have, and how bad your symptoms are. Small kidney stones that are less than 5 mm in diameter will usually pass on their own. You should drink at least 6 to 8 glasses of water per day to produce a large enough amount of urine to help bring the stone out.

Pain can be pretty bad when you pass a kidney stone, so your doctor may prescribe pain medicines to help as well as medications that will help the stone pass. Other medicines can decrease stone formation or help break down and remove the material that is causing you to make stones. You may need surgery if the stone is too large to pass, the stone is growing, or the stone is blocking your urine flow.

Kidney stones are painful, but you can usually pass them without causing permanent harm. However, kidney stones often come back, so you and your doctor will need to work on finding the cause of your stone. Lastly, delaying treatment can lead to serious complications, so if you think that you have kidney stones see your doctor right away.

 

Kidney stones - Animation

If you ever have severe pain in your belly or one side of your back that comes and goes suddenly, you may be passing a kidney stone. Let's talk about the painful condition of kidney stones.

A kidney stone is a mass of tiny crystals in your kidney or urinary tract. Stones are quite common, and tend to run in families. They can form in weeks or months when your urine contains too much of certain substances.

There are several kinds of kidney stones. Calcium stones are by far the most common kind. They often form in men between the ages of 20 to 30. Calcium can combine with other substances found in your food, like oxalate, phosphate, or carbonate, to form stones.

Cystine stones can form in people who have cystinuria, a condition passed down through families in which stones are made from an amino acid called cystine. Struvite stones are found mostly in women who have urinary tract infections. These stones can grow very large and can block the kidney, ureter, or bladder. Uric acid stones are more common in men than in women. They can occur in people who have a history of gout or are going through chemotherapy.

So, how do you know if you have kidney stones?

Well, you may not have symptoms until the stone move down the ureter tubes through which urine empties into your bladder. When this happens, the stones can block the flow of urine out of your kidneys. The main symptom is severe sharp pain that starts suddenly, usually in your belly or one side of your back, and it may go away just as quickly. Other symptoms can include abnormal urine color, blood in your urine, fever, chills, nausea, and vomiting.

So, what do you do about kidney stones?

Well, your health care provider will perform a physical exam. You may need blood tests, kidney function tests, and tests that look for crystals in your urine. Several imaging tests, like a CT scan, can see stones or a blockage in your urinary tract.

Treatment will depend on the type of stone you have, and how bad your symptoms are. Small kidney stones that are less than 5 mm in diameter will usually pass on their own. You should drink at least 6 to 8 glasses of water per day to produce a large enough amount of urine to help bring the stone out.

Pain can be pretty bad when you pass a kidney stone, so your doctor may prescribe pain medicines to help as well as medications that will help the stone pass. Other medicines can decrease stone formation or help break down and remove the material that is causing you to make stones. You may need surgery if the stone is too large to pass, the stone is growing, or the stone is blocking your urine flow.

Kidney stones are painful, but you can usually pass them without causing permanent harm. However, kidney stones often come back, so you and your doctor will need to work on finding the cause of your stone. Lastly, delaying treatment can lead to serious complications, so if you think that you have kidney stones see your doctor right away.

 
 
 
 

 

 
 
 
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