Kidney stones are hard deposits that develop when certain substances in urine become concentrated and form crystals. A stone may remain inside the kidney or move into the ureter, where it can cause pain, bleeding or urinary obstruction.
There is more than one type of kidney stone. The most common kidney stones are calcium-based stones, particularly calcium oxalate stones. Other important types include calcium phosphate, uric acid, struvite and cystine stones.
Knowing the stone type can be useful because the factors that contribute to one type may differ from those associated with another. Prevention and, in selected situations, medical treatment can therefore be tailored according to the stone's composition.
At Prabhakar Bhurke Clinic, Dr. Sandip Prabhakar Bhurke, super specialist nephrologist and transplant physician, provides individualized kidney evaluation for patients with kidney stones and related kidney-function concerns.
Which Kidney Stones Are Most Common?
Kidney stones are broadly classified according to their chemical composition.
The major types are:
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Calcium oxalate stones
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Calcium phosphate stones
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Uric acid stones
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Struvite stones
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Cystine stones
Calcium stones account for the largest proportion of kidney stones, with calcium oxalate being more common than calcium phosphate.
The exact composition can sometimes be determined by analyzing a stone that has passed or been removed.
1. Calcium Oxalate Kidney Stones
Calcium oxalate stones are the most common type of kidney stone. They develop when calcium combines with oxalate in the urine.
Factors that can contribute to calcium oxalate stone formation include:
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Low urine volume
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High urinary calcium
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High urinary oxalate
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Low urinary citrate
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High sodium intake
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Certain metabolic conditions
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Family history
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Some gastrointestinal conditions
Importantly, people who form calcium oxalate stones generally should not eliminate dietary calcium without medical advice. Adequate dietary calcium can help reduce intestinal absorption of oxalate.
Foods and Calcium Oxalate Stones
Depending on individual urine findings, a healthcare professional may recommend reducing excessive intake of high-oxalate foods.
Examples can include:
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Spinach
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Peanuts
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Certain nuts
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Rhubarb
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Wheat bran
However, dietary advice should be personalized rather than based on a blanket list of foods that everyone with stones must avoid.
2. Calcium Phosphate Stones
Calcium phosphate is another form of calcium-based kidney stone.
These stones may be associated with particular urinary and metabolic conditions, including abnormalities affecting urine chemistry.
Factors that may be relevant include:
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High urinary calcium
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Certain hormonal disorders
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Renal tubular disorders
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Higher urine pH in some patients
Because calcium phosphate and calcium oxalate stones have different chemical characteristics, identifying the composition can help guide prevention.
3. Uric Acid Kidney Stones
Uric acid stones form when urine contains conditions that favor uric acid crystallization, particularly persistently acidic urine.
Factors associated with uric acid stones can include:
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High intake of animal protein
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Gout
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Obesity
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Metabolic conditions
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Low urine volume
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Persistently acidic urine
Dietary patterns containing substantial amounts of meat, seafood and organ meats can increase uric acid production in susceptible people.
Unlike many calcium stones, some uric acid stones may be amenable to medical dissolution through carefully supervised urine alkalinization.
This should only be done under medical guidance because inappropriate treatment can cause other urinary problems.
4. Struvite Kidney Stones
Struvite stones are infection-related stones.
They can develop in association with certain urinary tract infections caused by bacteria that alter urine chemistry.
These stones can sometimes grow quickly and become large.
Possible concerns include:
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Recurrent urinary infections
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Large branching stones
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Urinary obstruction
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Kidney infection
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Reduced kidney function in complicated cases
Treatment generally requires management of the infection and, when necessary, removal of the stone burden.
A recurrent infection-associated stone should therefore be investigated rather than treated only as an isolated episode of urinary infection.
5. Cystine Kidney Stones
Cystine stones are uncommon compared with calcium stones.
They occur because of an inherited condition called cystinuria, in which the kidneys allow excessive amounts of cystine to enter the urine.
Because cystinuria is inherited, cystine stones may appear at a younger age and may recur.
People with recurrent or early-onset stones may need evaluation for an underlying metabolic or inherited cause.
Long-term prevention can require a specialized treatment plan, including individualized fluid and medication strategies.
How Can You Know Which Type of Kidney Stone You Have?
The appearance of a stone on an ultrasound or CT scan usually does not reliably tell you its exact chemical composition.
A doctor may use several sources of information, including:
Stone Analysis
If a stone is passed naturally or removed during a procedure, it may be sent for laboratory analysis.
Stone analysis can identify its composition and help guide prevention.
Urine Testing
Depending on the situation, urine testing may assess:
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pH
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Calcium
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Oxalate
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Uric acid
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Citrate
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Sodium
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Volume
Blood Tests
The doctor may evaluate:
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Kidney function
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Calcium
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Uric acid
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Electrolytes
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Other metabolic markers
24-Hour Urine Testing
People with recurrent, multiple or high-risk stones may be candidates for metabolic evaluation using a timed urine collection.
This can identify abnormalities that increase the likelihood of another stone.
What Causes Common Kidney Stones?
There is usually not one single cause.
Stone formation can be influenced by the interaction between urine chemistry, fluid intake, diet, genetics and medical conditions.
Important risk factors include:
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Not drinking enough fluid
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High urinary calcium
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High urinary oxalate
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Low urinary citrate
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High dietary sodium
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Certain dietary patterns
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Obesity
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Family history
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Gout
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Hyperparathyroidism
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Recurrent urinary infections
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Certain inherited disorders
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Some medications
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Urinary tract abnormalities
Low urine volume is particularly important because concentrated urine makes it easier for stone-forming substances to crystallize.
Do All Kidney Stones Cause Pain?
No.
A kidney stone may remain in the kidney without causing noticeable symptoms.
Pain is more likely when a stone moves into the ureter or interferes with urine flow.
Possible symptoms include:
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Sudden flank or side pain
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Pain radiating toward the abdomen or groin
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Blood in urine
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Nausea
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Vomiting
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Burning while urinating
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Frequent urination
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Urinary urgency
A stone that blocks urine flow can cause severe pain and may require prompt treatment.
Can Common Kidney Stones Damage the Kidneys?
Many uncomplicated kidney stones can be successfully managed, but complications can occur.
Potential problems include:
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Persistent urinary obstruction
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Recurrent urinary infections
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Kidney infection
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Blood in urine
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Declining kidney function in complicated cases
A larger stone, an obstructing stone or a stone associated with infection deserves appropriate medical evaluation.
How Are Common Kidney Stones Treated?
Treatment depends on several factors, including:
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Stone size
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Location
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Composition
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Degree of obstruction
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Symptoms
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Infection
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Kidney function
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Overall health
Observation
Some smaller stones may pass naturally and can be monitored when there is no dangerous obstruction or infection.
Pain Management
Appropriate pain treatment may be prescribed while a suitable stone is being observed or evaluated.
Medical Treatment
Selected patients may receive medicines that help stone passage or reduce the likelihood of future stones.
The medicine depends on the stone type and the patient's medical condition.
Shock Wave Lithotripsy
Shock waves can be used to fragment selected stones into smaller pieces.
Ureteroscopy and Laser Treatment
A ureteroscope can be passed through the urinary tract to reach a stone. Laser energy may then be used to fragment it.
Percutaneous Nephrolithotomy
PCNL may be considered for larger or more complex renal stone burdens.
Treatment should be selected according to the individual stone rather than simply its presence on a scan.
What Is the Best Way to Prevent Common Kidney Stones?
Prevention begins with understanding why the stone formed.
Drink an Appropriate Amount of Fluid
Adequate fluid intake helps dilute urine and can reduce the concentration of stone-forming substances.
However, fluid requirements vary. People with kidney failure, heart conditions or prescribed fluid restrictions should follow their healthcare team's advice rather than increasing fluids independently.
Reduce Excess Sodium
High sodium intake can increase the risk of calcium-containing stones.
Reducing heavily salted and highly processed foods may therefore be part of stone prevention.
Do Not Automatically Avoid Calcium
People with calcium oxalate stones should not assume that eliminating calcium from the diet will prevent stones.
Appropriate dietary calcium can actually help reduce oxalate absorption in the digestive tract.
Moderate Animal Protein When Appropriate
Excessive animal protein can contribute to urinary changes associated with some types of stones, particularly uric acid stones.
The appropriate amount should be individualized.
Maintain a Healthy Weight
Overweight and obesity are associated with increased kidney stone risk. Healthy weight management can therefore be part of prevention.
Can Kidney Stones Be Prevented With Home Remedies?
There is no universal home remedy that prevents or dissolves every type of kidney stone.
Some lifestyle measures can reduce risk, but prevention should be based on the patient's stone type and metabolic risk factors.
For example:
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Fluid intake may need adjustment.
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Sodium intake may need reduction.
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Oxalate intake may need modification in selected calcium oxalate stone formers.
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Animal protein may need moderation.
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Certain patients may require prescribed preventive medicines.
Unverified herbal preparations marketed as “kidney stone cleaners” should not replace medical evaluation.
When Is a Kidney Stone an Emergency?
Seek urgent medical attention when suspected or known kidney stones are accompanied by:
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Fever or chills
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Severe or worsening pain
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Persistent vomiting
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Very little or no urine
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Severe weakness
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Confusion
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Signs of serious infection
An obstructed urinary tract with infection can become a serious medical emergency and may require urgent drainage before definitive stone treatment.
Larger stones that block urine flow or cause severe symptoms may also require prompt treatment.
Who Is More Likely to Develop Kidney Stones?
Risk can be higher in people with:
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Previous kidney stones
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Family history of stones
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Low fluid intake
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Obesity
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Gout
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Hyperparathyroidism
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Recurrent urinary infections
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Certain bowel diseases
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Certain metabolic disorders
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Some inherited conditions
Having one kidney stone also increases the possibility of developing another in the future, which is why prevention is important after a first episode.
When Should a Kidney Stone Specialist Be Consulted?
Specialist evaluation is particularly useful when stones are:
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Recurrent
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Multiple
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Large
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Bilateral
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Associated with obstruction
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Associated with infection
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Associated with reduced kidney function
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Developing at a young age
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Difficult to clear
Patients with repeated stones may benefit from a more detailed metabolic evaluation rather than receiving treatment only for individual painful episodes.
Common Kidney Stone Evaluation at Prabhakar Bhurke Clinic
At Prabhakar Bhurke Clinic, Dr. Sandip Prabhakar Bhurke, super specialist nephrologist and transplant physician, provides individualized evaluation for patients with kidney stones and associated kidney-health concerns.
Depending on the clinical situation, assessment may include:
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Review of previous stone episodes
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Kidney-function evaluation
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Creatinine and eGFR testing
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Urine examination
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Assessment of urinary protein when appropriate
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Review of ultrasound or CT findings
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Stone composition assessment
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Evaluation of recurrent urinary infections
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Metabolic stone-risk evaluation
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Assessment of kidney damage or obstruction
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Long-term prevention planning
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Coordination with urological specialists when a stone-removal procedure is required
The goal is not only to address the current stone but also to understand why stones are forming and reduce the risk of recurrence.
Frequently Asked Questions
What is the most common kidney stone?
Calcium oxalate is the most common type of kidney stone. Calcium stones also include calcium phosphate stones.
What are the four main types of kidney stones?
The four major categories are calcium stones, uric acid stones, struvite stones and cystine stones. Calcium stones include calcium oxalate and calcium phosphate stones.
Are all kidney stones made of calcium?
No. Although calcium stones are the most common, kidney stones can also be made of uric acid, struvite or cystine.
Can kidney stones be dissolved with medicine?
Some uric acid stones may be medically dissolved by changing urine chemistry under specialist supervision. Most calcium stones are not simply dissolved with medication.
Should I stop eating calcium if I have kidney stones?
Not automatically. Appropriate dietary calcium can be beneficial for people prone to calcium oxalate stones. Dietary changes should be based on the stone type and individual medical evaluation.
Which kidney stones are caused by infection?
Struvite stones are associated with certain urinary tract infections and can sometimes grow rapidly.
Which kidney stones are inherited?
Cystine stones occur because of an inherited disorder called cystinuria.
Can kidney stones come back after treatment?
Yes. Removing a stone does not necessarily remove the metabolic, dietary or genetic factors that caused it. Stone analysis and appropriate preventive evaluation can help reduce recurrence.
Do common kidney stones always require surgery?
No. Some smaller stones may pass naturally. Larger, obstructing, infected or highly symptomatic stones may require active treatment.
Conclusion
Common kidney stones are not all the same. Calcium oxalate stones are the most frequently encountered, but calcium phosphate, uric acid, struvite and cystine stones also occur.
The type of stone can provide important clues about why it formed and how future stones may be prevented. Stone analysis, urine testing, blood tests and, in selected patients, metabolic evaluation can help create a more targeted prevention plan.
Treatment is determined by the stone's size, location, composition, symptoms, obstruction, infection status and kidney function. Small uncomplicated stones may sometimes pass naturally, while larger or complicated stones may need a procedure.
If you have recurrent kidney stones, bilateral stones, urinary obstruction, infections or abnormal kidney-function tests, specialist evaluation can help address both the current problem and the risk of future stones.
For individualized kidney evaluation and stone-related care, consult Dr. Sandip Prabhakar Bhurke at Prabhakar Bhurke Clinic.
Medical Disclaimer
This article is intended for general educational and informational purposes only and should not be considered a substitute for medical diagnosis, treatment or individualized medical advice. Kidney stones differ in composition, and the appropriate treatment depends on stone size, location, composition, obstruction, infection, kidney function and the patient's overall health. Dietary recommendations that are appropriate for one type of stone may not be appropriate for another. Do not begin restrictive diets, supplements, stone-dissolving medicines or herbal remedies without professional guidance. Seek urgent medical attention for severe pain with fever or chills, persistent vomiting, very little or no urine, confusion, severe weakness or rapidly worsening symptoms. Consult Dr. Sandip Prabhakar Bhurke or another qualified healthcare professional for personalized kidney stone evaluation and treatment.
