AI Summary Overview
What are Kidney Stones?
Kidney stones, also called renal calculi or nephrolithiasis, are solid crystal-like deposits that form in one or both kidneys when substances in urine become concentrated enough to crystallise. Stones vary greatly in size, shape and composition. Some are tiny and pass unnoticed, while others grow larger or become lodged in the urinary tract.
A stone may remain in the kidney without causing problems. Symptoms often begin when it moves into a ureter, the narrow tube that carries urine from the kidney to the bladder. A stone that blocks urine flow can increase pressure within the urinary tract. This causes severe pain that often comes in waves.
Most kidney stones can be treated successfully. However, recurrence is common, making prevention an important part of long-term care.
What are the Types of Kidney Stones?
Kidney stones are mainly classified according to their chemical composition. Identifying the stone type can help guide dietary changes, metabolic testing and preventive treatment. The common types of kidney stones are:
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Calcium Stones Calcium stones are the most common type of kidney stone. Most are made of calcium oxalate, while some contain calcium phosphate. Their formation can be influenced by low urine volume, high urinary calcium or oxalate levels, excess sodium intake and certain metabolic conditions. Having a calcium stone does not usually mean calcium should be removed from the diet. In fact, excessively restricting dietary calcium can increase oxalate absorption and may raise the risk of calcium oxalate stones in some people.
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Uric Acid Stones Uric acid stones form when urine remains too acidic, allowing uric acid to crystallise. They are more likely in people with persistently acidic urine and may be associated with conditions such as gout, obesity, metabolic syndrome or increased uric acid production. Unlike many calcium stones, some uric acid stones can be dissolved by medically supervised treatment that raises the urine pH.
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Struvite Stones Struvite stones develop in association with urinary tract infections caused by certain bacteria that alter urine chemistry. These stones may grow rapidly and can sometimes develop into large, branching stones that occupy a significant part of the kidney's collecting system. Treatment usually needs to address both the stone and the underlying infection.
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Cystine Stones Cystine stones are uncommon and occur in people with cystinuria, an inherited condition in which excessive amounts of cystine pass into the urine.
What are the Stages of Kidney Stones?
Kidney stones do not have formal disease stages based on severity. However, the process of passing a kidney stone through the urinary tract is commonly described in four stages, from its formation in the kidney to its eventual exit from the body.
These stages of kidney stones are:
| Stage | Features |
| Stage 1: Formation in the Kidney | Minerals and salts crystallise in concentrated urine and gradually form a stone inside the kidney. This stage is often painless. |
| Stage 2: Movement Into the Ureter | The stone enters the ureter and may partially or completely block urine flow, often causing severe, wave-like pain that can spread towards the lower abdomen or groin. |
| Stage 3: Entry Into the Bladder | The stone reaches the bladder. Severe flank pain may ease, while urinary pressure, urgency or frequency may become more noticeable. |
| Stage 4: Exiting the Body | The stone passes through the urethra during urination. There may be mild discomfort or blood in the urine as it exits. |
How Common are Kidney Stones in India?
Kidney stones are quite common in India. As per reports, kidney stones have a prevalence of 12 to 15% in India, with the condition more common in the northern part of the country. However, national data on the prevalence of kidney stones in the country is limited.
What are the Symptoms of Kidney Stones?
Kidney stones do not always cause symptoms. Some are discovered incidentally during imaging performed for another reason. Symptoms are more likely when a stone begins moving, irritates the urinary tract or blocks urine flow.
The common symptoms of kidney stones are as follows:
| Early Warning Signs | Severe or Complicated Symptoms |
| Mild or intermittent pain in the side or back | Severe, wave-like pain in the side or back that may spread towards the lower abdomen or groin |
| Blood in the urine | Persistent severe pain that remains difficult to control |
| Increased urinary urgency or frequency | Fever or chills with urinary symptoms |
| Burning or discomfort while passing urine | Persistent vomiting or inability to keep fluids down |
| Mild nausea associated with pain | Very little urine or inability to pass urine |
| Symptoms that come and go as the stone moves | Weakness, confusion or other signs of severe infection |
Diseases Similar to Kidney Stones
Several conditions can cause abdominal, back or side pain that may initially resemble kidney stone pain. The table below compares kidney stones with similar diseases like gallstones and appendicitis:
Kidney Stones vs. Gallstones vs. Appendicitis
| Feature | Kidney Stones | Gallstones | Appendicitis |
| How It Happens | Minerals and other substances crystallise in urine and form stones | Substances in the bile harden into stones within the gallbladder | The appendix becomes inflamed, often following blockage |
| Location | Pain often starts in the side or back and may move towards the lower abdomen or groin | Pain is usually in the upper right or central abdomen and may spread to the back or shoulder | Pain often begins around the centre of the abdomen and later moves to the lower right side |
| Associated Symptoms | Blood in urine, urinary urgency, nausea and vomiting | Nausea, vomiting and pain after meals may occur | Loss of appetite, nausea, fever and abdominal tenderness may occur |
| Severity | Ranges from silent stones to severe obstruction or infected obstruction | Ranges from symptom-free stones to inflammation or bile-duct obstruction | Can progress to perforation and abdominal infection if untreated |
| Can It Be Reversed? | Small stones may pass naturally, while others can be removed or broken up; recurrence is possible | Symptoms can be treated, and gallbladder removal may prevent future gallbladder stones | Usually resolves with appropriate treatment, which may include surgery |
What Causes Kidney Stones?
Kidney stones form when urine becomes concentrated with substances capable of forming crystals and the balance between stone-forming and stone-preventing factors is disturbed. The exact cause can differ depending on the type of kidney stone.
Common causes of kidney stones and their mechanisms include:
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Low Urine Volume: Inadequate fluid intake or excessive fluid loss makes urine more concentrated and increases the likelihood of crystal formation.
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High Urinary Calcium or Oxalate: Excess calcium or oxalate in urine can promote calcium-based stones.
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Persistently Acidic Urine: Low urine pH favours the formation of uric acid stones.
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Low Urinary Citrate: Citrate normally helps prevent calcium crystals from joining together. Low levels can increase stone formation.
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Urinary Infection: Certain bacteria alter urine chemistry and contribute to struvite stones.
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Inherited Disorders: Conditions such as cystinuria or primary hyperoxaluria can cause recurrent stone formation.
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Metabolic or Hormonal Disorders: Gout, hyperparathyroidism and renal tubular acidosis can alter urine composition.
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Digestive Disorders or Surgery: Chronic diarrhoea, inflammatory bowel disease and certain gastrointestinal procedures can affect fluid and oxalate handling and increase stone risk.
What are the Risk Factors for Kidney Stones?
Kidney stones can affect anyone, but several lifestyle, environmental, medical and genetic factors can increase the likelihood of developing them. The common risk factors for kidney stones are:
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Previous Kidney Stones: People who have already developed a stone have an increased risk of recurrence.
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Family History: Kidney stones can cluster within families because of shared genetic and metabolic factors.
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Low Fluid Intake: Inadequate hydration produces smaller amounts of more concentrated urine.
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Hot Climate or Heat Exposure: Heavy sweating without sufficient fluid replacement can increase urine concentration.
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High Sodium Intake: Excess salt can increase urinary calcium excretion and contribute to calcium stone formation.
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Excess Animal Protein: High intake can increase uric acid and make urine more acidic in susceptible people.
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Obesity and Metabolic Syndrome: Conditions like obesity and metabolic syndrome are associated with changes in urine chemistry that favour stone formation.
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Certain Medical Conditions: Gout, hyperparathyroidism, recurrent urinary infections, renal tubular acidosis and bowel disorders may increase risk.
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Certain Medicines and Supplements: Some medicines can alter urine chemistry or crystallise within the urinary tract.
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Prolonged Immobility: Reduced mobility and certain chronic illnesses can affect calcium metabolism and increase stone risk.
What are the Complications of Kidney Stones?
Most kidney stones do not cause permanent kidney damage when recognised and treated appropriately. Complications arise when a stone causes prolonged obstruction, infection or repeated episodes. The common complications of kidney stones are as follows:
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Urinary Obstruction and Hydronephrosis A stone lodged in the ureter can block normal urine flow. Urine may then build up above the obstruction and cause swelling of the kidney, known as hydronephrosis.
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Urinary Tract or Kidney Infection Urine trapped behind an obstruction can become infected. Infection combined with obstruction requires prompt treatment because bacteria may spread rapidly.
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Sepsis An infected obstructed urinary system can allow infection to spread into the bloodstream and cause sepsis. This is a medical emergency.
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Acute Kidney Injury Severe urinary obstruction can impair kidney function, particularly when both kidneys are affected or when a person has only one functioning kidney.
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Recurrent Kidney Stones Some people develop stones repeatedly and may require long-term metabolic testing, dietary modification and preventive treatment.
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Persistent Pain or Bleeding A stone can continue to cause renal colic or blood in the urine until it passes or is treated.
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Long-Term Kidney Damage Permanent kidney damage is uncommon after an uncomplicated kidney stone, but can occur with prolonged obstruction, recurrent infections, extensive stone burden or certain inherited stone disorders.
When Should I See a Healthcare Provider?
Medical assessment is recommended when kidney stone symptoms develop, as similar symptoms can occur with other abdominal, urinary or kidney conditions.
Seek medical advice if:
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You develop severe or recurrent pain in the side, back, lower abdomen, or groin.
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You notice visible blood in the urine.
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You experience persistent pain or burning while passing urine.
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Pain is accompanied by repeated vomiting.
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You cannot maintain adequate fluid intake.
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A known stone does not pass within the expected period.
How are Kidney Stones Diagnosed?
Diagnosis combines symptoms and medical history with urine tests, blood tests and imaging. The aim is not only to confirm the presence of a stone but also to determine its size and location, identify obstruction or infection and assess factors that may contribute to recurrence.
Common diagnostic measures recommended to diagnose kidney stones are as follows:
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Medical History and Examination A doctor may ask where the pain began, whether it moves towards the groin, whether there is blood in the urine, nausea, vomiting, fever or difficulty passing urine, and whether kidney stones have occurred previously. Information about fluid intake, diet, medicines, family history, bowel disease, gout and previous urinary infections may also be relevant.
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Urine Tests
Urinalysis may detect:
- Blood
- Signs of infection
- Urine pH
- Crystals
A urine culture may be performed if bacterial infection is suspected. People with recurrent or high-risk kidney stones may require one or more 24-hour urine collections to measure urine volume and substances such as calcium, oxalate, citrate, uric acid and sodium.
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Blood Tests
Blood tests may be used to assess:
- Kidney function
- Calcium
- Uric acid
- Electrolytes
Additional investigations may be performed when a metabolic or hormonal disorder is suspected.
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Imaging Tests Non-contrast CT of the kidneys, ureters and bladder can identify most urinary stones and determine their size, location and whether obstruction is present. Ultrasound avoids radiation and is commonly used when radiation exposure should be minimised, including during pregnancy and in children. A KUB X-ray can identify many calcium-containing stones, but cannot detect every stone type.
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Stone Analysis If a stone is passed naturally or removed during treatment, laboratory analysis can determine its chemical composition. Stone analysis is particularly helpful in recurrent disease, unusual stone types, stone formation at a young age or when an inherited or metabolic condition is suspected.
Diagnostic Summary Table
| Test or Assessment | What It Helps Determine |
| Urinalysis | Blood, urine pH, crystals and possible infection |
| Urine culture | Presence of bacterial urinary infection |
| Blood tests | Kidney function and metabolic abnormalities |
| Ultrasound KUB | Stones, hydronephrosis and urinary tract anatomy |
| Non-contrast CT KUB | Stone size, location and degree of obstruction |
| KUB X-ray | Certain radiopaque stones and follow-up |
| Stone analysis | Chemical composition of the stone |
| 24-hour urine testing | Metabolic factors contributing to recurrent stones |
How are Kidney Stones Treated and Managed?
Kidney stone treatment depends on the stone's size, location and composition, the severity of symptoms, whether urine flow is blocked, the presence of infection and kidney function. The common treatments recommended to patients with kidney stones are:
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Observation and Supportive Care Small stones that are not causing infection can often be managed with observation and supportive care without an immediate procedure.
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Medical Expulsive Therapy Selected ureteral stones may be managed with treatment intended to relax the ureter and improve the likelihood of spontaneous stone passage. This approach is used only when immediate removal is not required, and the person does not have complications such as infection, uncontrolled pain or deteriorating kidney function.
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Urinary Alkalinisation and Stone Dissolution Certain uric acid stones can sometimes be dissolved by increasing urine pH under medical supervision. Urine pH needs to be monitored carefully because excessive alkalinisation can encourage other types of stones. Most calcium stones cannot be dissolved using this approach.
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Shock Wave Lithotripsy Shock wave lithotripsy uses externally generated shock waves to break a suitable stone into smaller fragments that can then pass through the urinary tract.
Its effectiveness depends on factors such as:
- Stone size
- Stone location
- Stone density
- Body anatomy
More than one treatment session may occasionally be necessary.
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Ureteroscopy and Laser Lithotripsy Ureteroscopy involves passing a thin instrument through the urinary passage and bladder into the ureter or kidney. The stone can then be removed directly or broken into smaller fragments using laser energy. A temporary ureteral stent may sometimes be placed to maintain urine drainage while swelling settles.
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Percutaneous Nephrolithotomy Percutaneous nephrolithotomy, or PCNL, removes kidney stones through a small channel created through the back into the kidney. It is commonly considered for large renal stones, substantial stone burden and many staghorn stones because it can remove larger amounts of stone effectively.
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Open or Laparoscopic Surgery Open or laparoscopic surgery is rarely required now, as most kidney stones can be treated using shock waves, ureteroscopy or percutaneous procedures. It may still be considered in unusual anatomical situations or when less invasive treatments are unsuitable or unsuccessful.
Common Medicines Used to Treat Kidney Stones
Medicines have different roles in kidney stone management. Some relieve an acute attack, some can help selected stones pass, and others help prevent recurrence. Some common medicines prescribed by doctors are as follows:
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Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): These medicines reduce renal colic, the severe wave-like pain caused by a stone blocking the ureter. They may not suit people with certain kidney, stomach or cardiovascular conditions.
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Paracetamol: Paracetamol is used for acute kidney stone pain. The choice of pain relief depends on the person's health and clinical condition.
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Alpha-Blockers: Medicines such as tamsulosin or silodosin may help selected stones in the lower ureter pass. It is prescribed as an option for distal ureteral stones measuring 5-10 mm. This use is off-label.
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Alkaline Citrates: Medicines such as potassium citrate make urine less acidic. They are used for uric acid stones and certain other urine abnormalities linked with recurrent stones.
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Thiazide Diuretics: These may be prescribed when testing shows hypercalciuria, meaning excessive calcium in the urine, particularly in people forming recurrent calcium stones.
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Allopurinol: This medicine may be prescribed for hyperuricosuria, meaning excessive uric acid in the urine. It is not required for every person with a uric acid or calcium stone.
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Antibiotics: Antibiotics treat bacterial infections associated with a stone. They do not dissolve ordinary kidney stones. An infected obstruction also requires drainage rather than antibiotics alone.
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Tiopronin: This medicine may be used for cystine stones when fluid intake, urine alkalinisation and other measures do not adequately prevent recurrence.
Living With Kidney Stones: Daily Challenges and Caregiving
Kidney stones can disrupt everyday life during an acute attack and may also create ongoing concerns for people with recurrent stones. Some common challenges and caregiving associated with kidney stones are as follows:
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Challenges
- Sudden Pain Episodes: Renal colic can occur unexpectedly and disrupt work, sleep, travel and daily activities.
- Urinary Symptoms: Urgency, discomfort or blood in the urine can make everyday activities uncomfortable.
- Recurrence Concerns: People who have previously developed stones may need ongoing dietary changes, investigations and follow-up.
- Recovery After Treatment: Procedures and temporary ureteral stents can cause short-term discomfort or urinary symptoms.
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Patient Well-Being
- Maintain Appropriate Hydration: Regular fluid intake helps keep urine diluted unless fluid restriction has been medically advised.
- Follow Stone-Specific Advice: Dietary changes should be based on the stone type and metabolic findings rather than overly restrictive general diets.
- Attend Follow-Up: Repeat imaging, stone analysis or metabolic testing can help identify factors that increase the risk of recurrence.
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Expenses
- Consultation and Testing Costs: Urology appointments, urine tests, blood tests, imaging and stone analysis contribute to treatment expenses.
- Procedure Costs: Lithotripsy, ureteroscopy, laser treatment or PCNL may be required for stones that cannot pass safely.
- Recurring Care Costs: Recurrent stone disease can result in ongoing expenses for metabolic testing, preventive medicines and repeat imaging.
What is the Prognosis for Kidney Stones?
The outlook for kidney stones is generally favourable when they are identified and treated appropriately. Many small ureteral stones pass spontaneously. Stones that do not pass can usually be treated successfully using minimally invasive procedures. Kidney function generally recovers when obstruction is relieved before permanent damage occurs.
Recurrence is an important long-term concern. People who have formed one kidney stone have an increased likelihood of developing another, particularly when underlying metabolic, dietary or genetic risk factors remain. Stone analysis, adequate hydration and targeted dietary or medical prevention can reduce the risk of recurrence.
Long-term kidney damage is uncommon after an uncomplicated episode but becomes more likely with prolonged obstruction, recurrent infection, extensive stone burden or certain inherited disorders.
How Can I Prevent Kidney Stones?
Not every kidney stone can be prevented, particularly when inherited or underlying medical conditions are involved. However, some common practices that can help prevent kidney stones are as follows:
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Drink enough fluid to keep urine well-diluted.
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Increase fluid intake during hot weather, exercise, or work involving heavy sweating.
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Prefer water as the main source of hydration.
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Maintain normal age-appropriate dietary calcium rather than routinely eliminating calcium.
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Limit excessive salt intake.
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Avoid excessive animal protein when it contributes to an individual's stone risk.
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Limit high-oxalate foods when calcium oxalate stones or high urinary oxalate make this necessary.
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Maintain a healthy body weight.
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Follow treatment for conditions such as gout, hyperparathyroidism, recurrent urinary infections, or bowel disorders.
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Have passed or removed stones analysed when possible, so prevention can be tailored to the actual stone type.
For many adults with recurrent stones, sufficient fluid intake to produce more than approximately 2–2.5 litres of urine per day may be recommended. The required fluid intake varies and should be individualised for people with heart, kidney or other conditions that require fluid restriction.
Kidney Stones Treatment Cost in India
Kidney stone treatment costs in India vary according to the city, hospital, stone size and location, imaging required, procedure performed, anaesthesia, stent placement and length of hospital stay. The estimated treatment costs for kidney stones are as follows:
| Test or Treatment | Approximate Cost |
| Kidney ultrasound | ₹1,200-₹2,500 |
| Computed Tomography (CT) scan | ₹3,000-₹10,000 |
| Extracorporeal Shock Wave Lithotripsy (ESWL) | ₹30,000-₹50,000 |
| Ureteroscopy | ₹25,000-₹85,000 |
| Percutaneous Nephrolithotomy (PCNL) | ₹70,000-₹1,50,000 |
| Hospital Stay | ₹5,000-₹15,000 per day |
Note: These figures are indicative and may vary in reality. Additional expenses may include blood and urine tests, anaesthesia, medicines, ureteral stent placement or removal, and follow-up imaging.
Does Health Insurance Cover Kidney Stones in India?
Yes. Health insurance covers the treatment for kidney stones in India. It pays for medically necessary hospitalisation or day care treatment for kidney stones, depending on the terms of the policy. Eligible treatments may include procedures such as:
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Ureteroscopy
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Laser lithotripsy
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Shock wave lithotripsy
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Percutaneous nephrolithotomy
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Ureteral stent procedures
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Emergency hospital admission
Outpatient consultations, medicines and diagnostic tests may be covered with the OPD benefit. However, the exact coverage may vary from one policy to another.
However, kidney stones will be covered after a waiting period. If kidney stones were detected before buying the policy, it will be considered a pre-existing disease and a waiting period of up to 36 months may apply.
Note: Coverage may also be affected by co-payments, room-rent restrictions, procedure sub-limits and policy exclusions.
How Much Health Insurance Coverage is Needed for Kidney Stones Treatment?
There is no fixed kidney stone-specific sum insured that is suitable for everyone.
A health insurance cover of approximately ₹5 to ₹10 lakh may be suitable to meet basic kidney stone treatment and hospitalisation expenses. A higher coverage of ₹15 to ₹20 lakh may be opted for to provide broader protection against major complications.
FAQs
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Q1. Can kidney stones pass on their own?
Ans: Yes. Many small ureteral kidney stones can pass naturally. Although the likelihood depends mainly on their size and location. -
Q2. Are all kidney stones made of calcium?
Ans: No. Kidney stones can be made of uric acid, struvite and cystine stones, in addition to calcium. -
Q3. Does drinking less water cause kidney stones?
Ans: Low fluid intake is an important risk factor associated with kidney stones because concentrated urine makes crystals more likely to form.
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References
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https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/definition-facts
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https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/symptoms-causes
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https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/diagnosis
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https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/treatment
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https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/eating-diet-nutrition
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https://pmc.ncbi.nlm.nih.gov/articles/PMC11618031/
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https://www.niddk.nih.gov/health-information/urologic-diseases/bladder-infection-uti-in-adults/symptoms-causes
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https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-infection-pyelonephritis
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https://irdai.gov.in/health-dept
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https://www.medicoverhospitals.in/articles/kidney-stone-scan-cost
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https://www.medicoverhospitals.in/surgery-cost/ureteroscopy-cost
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https://www.carehospitals.com/surgery-cost/lithotripsy-cost
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https://www.apollohospitals.com/procedures/percutaneous-nephrolithotomy-pcnl
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https://pmc.ncbi.nlm.nih.gov/articles/PMC10060047/#REF2
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https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones
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