Nephrolithiasis with Infection (Struvite Stones)
What is Nephrolithiasis with Infection (Struvite Stones)?
Struvite stones are a type of kidney stone that forms because of bacterial infection in your urinary tract. These stones are also called infection stones. They develop when certain bacteria produce an enzyme called urease that breaks down urea in your urine. This process creates an alkaline environment that causes minerals like magnesium, ammonium, and phosphate to crystallize and form stones.
Struvite stones are different from the more common calcium stones because they grow rapidly and can become very large. They often take on a branching shape called a staghorn calculus that fills the kidney's collecting system. These stones account for about 10 to 15 percent of all kidney stones. Women develop struvite stones more often than men because urinary tract infections are more common in women.
The presence of infection makes struvite stones particularly concerning. Antibiotics alone cannot eliminate the infection because bacteria hide within the stone structure. Complete stone removal is usually necessary to clear the infection and prevent it from coming back. Without treatment, these stones can damage your kidneys and lead to serious complications.
Symptoms
- Fever and chills from active infection
- Pain in your back, side, or lower abdomen
- Cloudy or foul-smelling urine
- Blood in your urine
- Frequent urge to urinate
- Burning sensation when urinating
- Nausea and vomiting
- Feeling generally unwell or fatigued
Some people with struvite stones may not notice symptoms right away if the infection is mild. However, as stones grow larger, symptoms usually become more noticeable. Large staghorn stones can cause dull, persistent pain even without obvious infection signs.
Concerned about Nephrolithiasis with Infection (Struvite Stones)? Check your levels.
Screen for 1,200+ health conditions
Causes and risk factors
Struvite stones form when urease-producing bacteria infect your urinary tract. Common bacteria that cause these stones include Proteus mirabilis, Klebsiella, Pseudomonas, and some types of Staphylococcus. These bacteria split urea molecules into ammonia and carbon dioxide. The ammonia makes your urine more alkaline, which promotes crystal formation. The infection also releases inflammatory substances that help crystals stick together and form stones.
Several factors increase your risk of developing struvite stones. Women face higher risk due to shorter urethras that allow bacteria easier access. People with recurring urinary tract infections are much more susceptible. Other risk factors include urinary catheters or stents, neurogenic bladder, incomplete bladder emptying, structural abnormalities in the urinary tract, and previous kidney stones. Having a condition that affects urine flow or bladder function significantly raises your risk.
How it's diagnosed
Doctors diagnose struvite stones through a combination of imaging tests and urine analysis. A CT scan without contrast is the most accurate way to see kidney stones and determine their size and location. Ultrasound can also detect larger stones and is often used for initial screening. X-rays may show struvite stones because they typically contain calcium and appear visible on film.
Urine testing plays a critical role in diagnosing infection stones. Your doctor will order a urinalysis to check for signs of infection. Tests like urine leukocyte esterase detect white blood cells in your urine, which indicate active infection. A urine culture identifies the specific bacteria causing the infection. Rite Aid offers testing that includes urine leukocyte esterase to help detect urinary tract infections early. Blood tests may also check your kidney function and look for signs of infection spreading to your bloodstream.
Treatment options
- Surgical stone removal through procedures like percutaneous nephrolithotomy or ureteroscopy
- Antibiotics to treat the active infection, though they cannot eliminate bacteria within the stone
- Increased fluid intake to help flush your urinary system and prevent new stones
- Urinary acidifiers like acetohydroxamic acid to inhibit urease enzyme activity in some cases
- Treatment of underlying conditions that affect urine flow or bladder emptying
- Regular follow-up imaging to monitor for stone recurrence
- Preventive antibiotics in some cases to reduce infection risk after stone removal
Complete stone removal is essential because antibiotics alone cannot cure the infection. Even small fragments left behind can harbor bacteria and lead to stone regrowth. Work closely with a urologist who specializes in kidney stone treatment to develop the best plan for your situation.
Concerned about Nephrolithiasis with Infection (Struvite Stones)? Get tested at Rite Aid.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Struvite stones form because of bacterial infection, not from diet or metabolism like most other stones. They grow much faster than calcium stones and can become very large in a short time. Unlike other stone types, antibiotics alone cannot treat them because bacteria hide inside the stone structure. Complete surgical removal is usually necessary.
No, struvite stones rarely pass on their own because they typically grow too large. These stones often develop into staghorn calculi that branch throughout the kidney. Treatment requires surgical removal to eliminate both the stone and the infection. Leaving them untreated can lead to kidney damage and serious infections.
Struvite stones can grow remarkably fast compared to other kidney stones. In the presence of ongoing infection, they may increase in size by several millimeters per week. Some can develop into large staghorn stones within just a few months. This rapid growth makes early detection and treatment important.
A staghorn calculus is a large kidney stone that branches into multiple parts of the kidney's collecting system. It gets its name because the branching pattern looks like deer antlers. Struvite stones commonly form this shape because they grow so rapidly. Staghorn stones require surgical removal and can cause serious kidney damage if left untreated.
Doctors use imaging tests like CT scans or ultrasounds to see the stones. Urine tests check for signs of infection, including white blood cells detected by leukocyte esterase testing. A urine culture identifies which bacteria are causing the infection. Blood tests may check kidney function and look for signs of systemic infection.
Women develop struvite stones more frequently because they have shorter urethras. This anatomy makes it easier for bacteria to enter the urinary tract and cause infections. Women also experience urinary tract infections at much higher rates overall. Since struvite stones form from bacterial infections, the increased infection risk translates to higher stone risk.
Prevention focuses on avoiding urinary tract infections and treating them promptly when they occur. Drinking plenty of water helps flush bacteria from your system. Urinating after sexual activity and practicing good hygiene reduces infection risk. If you have recurring infections or urinary problems, working with a doctor to address underlying causes is important.
Untreated struvite stones can cause ongoing kidney infections that lead to permanent kidney damage. The infection can spread to your bloodstream and cause sepsis, a life-threatening condition. Large stones can block urine flow and destroy kidney tissue. Chronic infection and obstruction may eventually lead to kidney failure requiring dialysis.
Struvite stones can recur if all stone fragments are not completely removed or if underlying infection risks remain. About 10 to 20 percent of people develop new stones within a few years. Prevention involves treating any residual infection, addressing urinary tract problems, and monitoring for new infections. Regular follow-up with imaging helps catch recurrence early.
Antibiotics treat the active infection but cannot eliminate bacteria within the stone itself. Acetohydroxamic acid can inhibit the urease enzyme that bacteria use to create stone-forming conditions. However, this medication has significant side effects and is not commonly used. The primary treatment remains surgical stone removal combined with appropriate antibiotics for the infection.