Kidney stones are hard deposits that form from minerals and other substances concentrated in the urine. Some stones remain in the kidney without causing symptoms, while others move into the ureter and can cause severe pain, bleeding or blockage of urine. At Providence Saint John’s Health Center, our urology specialists evaluate the size, location and type of kidney stone to determine whether it can pass naturally or requires treatment.
About the Kidneys and Kidney Stones
The kidneys filter the blood, remove waste and excess water, and produce urine. Kidney stones can form when minerals and other substances become highly concentrated in the urine and crystallize. Stones vary considerably in size and composition, and these differences can influence whether a stone is likely to pass naturally, require treatment or recur in the future.
How Do Kidney Stones Cause Pain?
A stone can remain within the kidney without causing noticeable symptoms. Pain often begins when a stone moves into the ureter, the narrow tube that carries urine from the kidney to the bladder, and interferes with urine flow. Pressure can then build within the urinary tract, producing severe pain in the side or back that may move toward the lower abdomen or groin.
The medical term for stones within the urinary system is urolithiasis. Stones located within the kidney may be called nephrolithiasis, while a stone that has moved into the ureter is sometimes described as ureterolithiasis. For treatment decisions, the size and location of the stone and whether it is obstructing urine flow are more important than the terminology itself.
What Are the Different Types of Kidney Stones?
Kidney stones can form from different substances within the urine. When a stone is passed naturally or removed during treatment, laboratory analysis can identify its composition. Blood testing and urine testing, including a 24-hour urine collection for selected patients, can help identify metabolic or other conditions that may be contributing to stone formation.
- Calcium stones: The most common type, usually composed of calcium oxalate or calcium phosphate.
- Uric acid stones: These can develop when urine contains persistently high levels of uric acid or is overly acidic.
- Struvite stones: These stones can develop in association with certain urinary tract infections and may grow rapidly.
- Cystine stones: These uncommon stones occur in people with cystinuria, an inherited condition that causes excessive cystine to enter the urine.
What Are the Symptoms of Kidney Stones?
Symptoms depend on the size and location of the stone and whether it is obstructing the urinary tract. A stone that remains within the kidney may cause few or no symptoms, while a stone moving through the ureter can produce sudden and sometimes intense discomfort.
- Severe or persistent pain in the side or back
- Pain that moves toward the lower abdomen or groin
- Nausea or vomiting
- Blood in the urine
- Pain or burning with urination
- Feeling the need to urinate more frequently or urgently
- Difficulty passing urine
When Does a Kidney Stone Require Urgent Care?
A kidney stone that blocks urine flow can sometimes lead to infection or impaired kidney function. Fever or chills with urinary obstruction, inability to urinate, uncontrolled pain or vomiting, or other signs of serious illness require prompt medical evaluation. An infected and obstructed kidney can become a medical emergency and may require urgent drainage before the stone itself is definitively treated.
What Increases the Risk of Kidney Stones?
Kidney stones often develop because of a combination of factors that affect the concentration and chemical balance of the urine. Some people experience a single stone, while others have metabolic, genetic, dietary or medical factors that make stones more likely to recur.
Hydration, Diet and Metabolic Health
Not drinking enough fluid allows urine to become more concentrated and is one of the most important modifiable contributors to kidney stone formation. Dietary patterns, excess body weight and certain metabolic conditions can also change urine chemistry and increase the likelihood that crystals will form.
Family and Personal History
People who have previously developed a kidney stone have an increased likelihood of developing another. A family history of kidney stones can also increase risk, particularly when inherited conditions affect how minerals or other substances are processed by the kidneys.
Digestive Conditions and Surgery
Inflammatory bowel disease, chronic diarrhea and certain gastrointestinal or bariatric surgical procedures can alter the way the body absorbs water, calcium, oxalate and other substances. These changes can affect urine composition and increase stone risk in some patients.
Urinary Infection and Other Medical Conditions
Certain recurrent urinary infections can contribute to struvite stone formation. Gout, cystinuria, abnormalities of calcium metabolism and other medical conditions can also increase the likelihood of particular types of kidney stones.
Medications and Supplements
Certain prescription medications and dietary supplements can increase kidney stone risk by changing urine chemistry or the concentration of stone-forming substances. Patients with recurrent stones should review medications and supplements with their physician rather than stopping prescribed treatment on their own.
Kidney Stones and Parathyroid Disease
Recurrent calcium kidney stones can sometimes be associated with primary hyperparathyroidism, a condition in which one or more parathyroid glands produce too much parathyroid hormone. This can raise calcium levels in the blood and urine, increasing the likelihood that calcium-containing kidney stones will form.
When blood testing or a history of recurrent stones suggests abnormal calcium metabolism, additional evaluation may help determine whether parathyroid disease is contributing to the problem. You can learn more about how hyperparathyroidism affects calcium levels and kidney stone risk through the Center for Endocrine Tumors and Disorders.
Can a Kidney Stone Pass on Its Own?
Many small stones can pass through the urinary tract without a procedure. The likelihood of spontaneous passage depends on the stone’s size and location as well as the patient’s anatomy, symptoms and whether urine flow is obstructed. Larger stones and stones that remain lodged in the ureter are less likely to pass without treatment.
When it is safe to allow a stone time to pass, treatment may include pain management, hydration guidance and medication to help the ureter relax. Follow-up is important to confirm that the stone has passed and that the kidney is draining normally.
How Are Kidney Stones Diagnosed?
Diagnosis begins with a review of symptoms, medical history and previous kidney stones or urinary conditions. Testing helps determine whether a stone is present, where it is located, how large it is and whether it is interfering with urine flow. For patients with recurrent stones, additional testing can help identify why stones continue to form.
CT Scan
A noncontrast CT scan can provide detailed information about the size and location of urinary stones and can show whether a stone is causing obstruction or swelling of the kidney. CT imaging can be particularly useful when symptoms are severe, the diagnosis is uncertain or detailed anatomical information is needed for treatment planning.
Kidney Ultrasound
Ultrasound uses sound waves to examine the kidneys and urinary tract without exposing the patient to radiation. It can identify many kidney stones and can show hydronephrosis, or swelling of the kidney caused by impaired urine drainage.
Blood and Urine Tests
Blood tests can evaluate kidney function and measure substances such as calcium and uric acid that may contribute to stone formation. Urine testing can identify blood, infection, crystals and other abnormalities that help guide diagnosis and treatment.
Stone Analysis and Metabolic Evaluation
When a stone is passed or removed, analyzing its composition can provide important information about why it formed. Patients with recurrent stones or other risk factors may also undergo a 24-hour urine collection to measure urine volume and levels of calcium, oxalate, uric acid, citrate, sodium and other substances associated with stone formation.
How Are Kidney Stones Treated?
Treatment depends on the stone’s size, location and composition; the severity of symptoms; whether urine flow is obstructed; and whether infection or other complications are present. Some stones can be safely monitored while they pass naturally, while others require a procedure to break apart or remove the stone.
Observation and Medical Management
When a stone is likely to pass and there are no signs of infection or significant obstruction, a period of observation may be appropriate. Treatment can include pain control, guidance about fluid intake and follow-up imaging or evaluation to make sure the stone has passed and normal urine flow has been restored.
Medication to Help a Stone Pass
For selected ureteral stones, an alpha-blocker such as tamsulosin may be prescribed to relax the ureter and facilitate stone passage. Medication is not appropriate for every stone, and its potential benefit depends on factors including the stone’s size and location.
Shock Wave Lithotripsy (SWL)
Shock wave lithotripsy uses focused energy from outside the body to break a kidney or ureteral stone into smaller fragments that can pass through the urinary tract. Imaging is used to locate the stone and direct the treatment. Whether SWL is appropriate depends on factors such as stone size, location and density as well as the patient’s anatomy and overall clinical circumstances.
Ureteroscopy with Laser Lithotripsy
Ureteroscopy is a minimally invasive procedure performed without an external incision. A thin ureteroscope is passed through the urethra and bladder and into the ureter or kidney, allowing the urologist to directly visualize the stone. Laser energy can then fragment the stone into smaller pieces that are removed or allowed to pass naturally.
A temporary ureteral stent may be placed after treatment to keep the ureter open while swelling resolves and urine drains from the kidney. Stents can temporarily cause urinary frequency, urgency, blood in the urine or discomfort, and the timing of removal is individualized according to the procedure and patient’s condition.
Percutaneous Nephrolithotomy (PCNL)
PCNL is used primarily for larger, complex or difficult-to-treat kidney stones. Through a small incision in the back, the urologist creates a direct pathway into the kidney and uses specialized instruments to break apart and remove the stone. This approach can allow treatment of a substantial stone burden that may not be well suited to ureteroscopy or shock wave lithotripsy.
Urgent Treatment for Infection or Obstruction
When a stone blocks urine flow and infection is present, the immediate priority is safely draining the affected kidney and treating the infection. A ureteral stent or a drainage tube placed through the back into the kidney may be used to restore urine flow. Definitive stone treatment is generally performed after the infection has been controlled and the patient is medically stable.
How Can Future Kidney Stones Be Prevented?
Kidney stones can recur, but understanding why a stone formed can help reduce the likelihood of another episode. Prevention is individualized according to stone composition, urine chemistry, medical conditions, diet and other risk factors rather than relying on the same recommendations for every patient.
Drink Enough Fluid
Keeping urine adequately diluted is one of the most important ways to reduce the risk of many types of kidney stones. Fluid needs vary with body size, activity, climate, medical conditions and previous stone history, so patients with recurrent stones may receive individualized hydration goals.
Use Stone Analysis and Urine Testing to Guide Prevention
Knowing what a stone is made of can help guide prevention. For recurrent stone formers, a 24-hour urine evaluation can identify abnormalities that may be addressed through changes in fluid intake, nutrition or medication.
Make Nutrition Changes Based on Stone Type
Dietary recommendations depend on the type of stone and the patient’s urine chemistry. Changes may include reducing excess sodium, modifying animal-protein intake or adjusting foods high in oxalate when appropriate. Patients should not automatically eliminate calcium from their diet because normal dietary calcium can be important and may actually help reduce the risk of some calcium oxalate stones.
Treat Underlying Medical Conditions
Conditions such as hyperparathyroidism, gout, recurrent urinary infection, digestive disorders and other metabolic abnormalities can contribute to recurring stones. Identifying and treating an underlying condition can therefore become an important part of long-term stone prevention.
Preventive Medication
Some patients with recurrent stones benefit from medication designed to correct a specific abnormality in urine chemistry or reduce formation of a particular stone type. Medication is selected according to stone analysis, laboratory findings and the patient’s individual medical history.
Personalized Kidney Stone Care at Saint John’s
At Providence Saint John’s Health Center, our urology specialists evaluate both the immediate kidney stone and the factors that may have caused it to form. Treatment can range from allowing a stone to pass naturally to minimally invasive procedures such as shock wave lithotripsy, ureteroscopy with laser treatment and PCNL when intervention is necessary.
For patients with recurrent stones, care can extend beyond removing the current stone to identifying metabolic, dietary, genetic or other medical contributors. When another condition such as parathyroid disease is involved, coordination across specialties can help address the underlying cause as well as the kidney stones themselves.
If you have kidney stone symptoms, recurring stones or questions about preventing another episode, our urology specialists can help determine the cause and develop a treatment and prevention plan personalized to you.
If you have questions regarding kidney stone treatment, please call today. Click here to request an appointment.
