Cystinuria: Causes, Symptoms, and Treatment
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Cystinuria?
A nephrologist, a doctor who treats kidney problems, or a urologist, a doctor who treats the urinary tract, usually treats cystinuria. A geneticist, a doctor who studies inherited conditions, may also help. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is cystinuria?
Cystinuria is a rare condition that is passed down through families. In it, the amino acid cystine builds up in the kidneys and bladder. An amino acid is a building block of protein.
Normally, the kidneys filter blood to make urine. They also take cystine back into the blood. People with cystinuria cannot take cystine back in the right way, so it collects in the urine.
As urine gets more concentrated, the extra cystine forms crystals. Larger crystals become stones. Cystinuria is a chronic, lifelong condition.
Symptoms
The condition is most often found after an episode of kidney stones. Symptoms include:
- Blood in the urine.
- Flank pain, which is pain in the side or back. It is most often on one side. It is often severe and may get worse over days.
- Pain in the pelvis, groin, or genitals, or between the upper belly and back.
Stones can block the urinary tract. They can also make it harder for the kidneys to remove waste. Bacteria can cause infections around stones. Other possible problems include injury to the bladder or kidney, kidney infection, chronic kidney disease, and a blocked ureter. A ureter is a tube that carries urine from a kidney to the bladder.
Causes and who gets it
Cystinuria is caused by too much cystine in the urine. Changes in the SLC3A1 or SLC7A9 gene cause it. These genes help make a protein that normally helps the kidneys take cystine back into the blood.
The condition is inherited in an autosomal recessive pattern. To have symptoms, you must inherit a changed gene from both parents. Parents who each carry one changed gene typically do not show signs of the condition.
Cystine stones are most common in young adults under age 40. Less than 3% of urinary tract stones are cystine stones.
How doctors diagnose it
Doctors test the stones after they are removed. This shows that they are made of cystine. Unlike calcium-containing stones, cystine stones do not show up well on plain x-rays.
Other tests that may be done include a 24-hour urine collection, an abdominal CT scan or ultrasound, an intravenous pyelogram (IVP), and a urinalysis, which is a urine test.
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.
- Drink plenty of fluids, especially water, to make large amounts of urine. The usual advice is at least 6 to 8 glasses per day, but people who have had cystine stones may need to drink even more. Ask your provider how much is right for you. Drink water at night too.
- Make the urine more alkaline, which may help dissolve cystine crystals. This may be done with potassium citrate or sodium bicarbonate.
- Eat less salt. It can decrease cystine release and stone formation.
- Ask your provider about medicines that help keep cystine from forming a stone, and about their side effects.
- Pain relievers may be needed when you pass stones.
Smaller stones (5 mm or less) most often pass on their own. Larger stones (more than 5 mm) may need extra treatment. Some large stones are removed with procedures:
- Shock wave lithotripsy (ESWL) uses sound waves to break stones into small pieces. It may not work well for cystine stones because they are very hard.
- Percutaneous nephrolithotomy places a small tube through the flank into the kidney. A telescope is passed through it to break up the stone.
- Ureteroscopy with laser lithotripsy uses a laser to break up stones that are not too large.
Without treatment, stones commonly return.
When to see a doctor
See a health care professional right away if you have sharp pain in your back, side, belly, or groin, blood in your urine, or you cannot urinate or pass only a little urine. Fever and chills can also occur with kidney stones, so tell a health care professional right away if they happen.
Call 911 or go to the emergency room if you faint, have trouble breathing, have a sudden change in mental status such as confusion, or have severe or persistent vomiting.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either kind of doctor can review your symptoms, arrange tests, and refer you to a kidney or urinary tract specialist. Because cystinuria is lifelong, they can also help with follow-up care over time.
Common questions
Is cystinuria a lifelong condition?
Yes. Cystinuria is a chronic, lifelong condition. Without treatment, stones commonly return.
Can cystinuria cause kidney failure?
Rarely. The condition rarely results in kidney failure. Stones can still cause problems like kidney infection or chronic kidney disease.
Do both of my parents need to have cystinuria for me to have it?
No. Each parent carries one changed gene and typically shows no signs. To have symptoms, you must inherit a changed gene from both parents.
Does drinking water help with cystinuria?
Yes. Treatment involves drinking plenty of fluids, especially water, to make large amounts of urine. This helps prevent more stones from forming.
Sources
- MedlinePlus Genetics - Cystinuria
- MedlinePlus - Cystinuria (Medical Encyclopedia)
- NIDDK - Treatment for Kidney Stones
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
