Reviewed by Mr Neil Haldar – August 2026
Kidney stones affect around 1 in 11 people in the UK at some point in their lifetime, and around 50% of people who form one stone will form another within 5–10 years if no preventive measures are taken. Most small stones (<5 mm) pass spontaneously with adequate fluid intake and pain relief. Larger stones, those causing persistent obstruction, or stones that fail to pass usually need active treatment.
The two most common modern treatments are ureteroscopy with laser stone fragmentation (URS) and extracorporeal shock wave lithotripsy (ESWL). The right choice depends on stone size, location, density, and your individual anatomy. Beyond surgical removal, metabolic work-up and prevention are the most important steps for anyone who has formed two or more stones — yet they are too often missed in routine NHS care.
This service offers comprehensive private stone management: rapid CT diagnosis, ureteroscopy and ESWL, stent management, 24-hour urine metabolic work-up with personalised prevention advice, and laparoscopic endopyelotomy for selected upper tract obstruction. For very large or staghorn stones requiring percutaneous nephrolithotomy (PCNL), Mr Haldar refers to specialist colleagues.
Important: Seek urgent medical assessment if stone pain is accompanied by fever, rigors, severe illness, persistent vomiting, inability to pass urine or reduced urine output. An infected obstructed kidney is a urological emergency because it can lead rapidly to sepsis and requires urgent drainage.
For a detailed explanation of stone types, symptoms, CT diagnosis and the different treatment options, read my complete guide to kidney stones.
About Mr Neil Haldar
Mr Neil Haldar is a Consultant Urological Surgeon at Buckinghamshire Healthcare NHS Trust with over 20 years’ experience in stone disease — diagnosis, surgical treatment, and metabolic prevention.
His private stone practice covers the full elective stone pathway:
- Ureteroscopy with laser stone fragmentation (URS) for ureteric and renal stones
- Extracorporeal shock wave lithotripsy (ESWL) for selected stones
- Ureteric stent insertion and management
- Metabolic stone work-up — 24-hour urine collection, blood tests, stone analysis, and personalised dietary advice
- Laparoscopic endopyelotomy for selected pelvi-ureteric junction obstruction
- Long-term stone surveillance for recurrent stone formers
For very large stones (typically >2 cm) or staghorn calculi requiring percutaneous nephrolithotomy (PCNL), Mr Haldar refers to specialist colleagues with high-volume PCNL practice. This deliberate scope ensures every patient is matched to the right procedure for their stone burden.
GMC: 3683914 | BUPA Platinum Consultant | MBBS MD FRCS (Eng) FRCS (Urol)
About Kidney Stones
Key Facts
| UK lifetime risk | Around 1 in 11 |
| Risk in men vs women | Approximately twice as common in men |
| Average age at first stone | 30–50 |
| Recurrence within 5–10 years | Approximately 50% if no prevention |
| Most common stone type | Calcium oxalate (around 70%) |
| Stones <5 mm | Around 80% pass spontaneously |
| Stones 5–10 mm | Around 50% pass spontaneously |
| Stones >10 mm | Usually need treatment |
What Are Kidney Stones?
Kidney stones (renal calculi) are hard mineral deposits that form within the urinary tract — most commonly in the kidneys, but they can also form in the ureters or bladder. They develop when the urine becomes concentrated and certain minerals — calcium, oxalate, uric acid, or cystine — crystallise and aggregate.
Stones cause problems when they:
- Move into the ureter — producing the characteristic severe pain of renal colic
- Block urine flow — leading to kidney swelling (hydronephrosis) and potential damage
- Cause infection — particularly urgent when combined with obstruction
- Cause bleeding — visible or microscopic haematuria
- Impair kidney function — particularly with chronic obstruction or recurrent stones
Types of Kidney Stones
Different stone types have different causes and prevention strategies:
| Stone Type | Approximate Frequency | Common Causes |
|---|---|---|
| Calcium oxalate | ~70% | Diet, genetic factors, dehydration, hypercalciuria |
| Calcium phosphate | ~10% | Renal tubular acidosis, hyperparathyroidism, alkaline urine |
| Uric acid | ~10% | Acidic urine, gout, high purine intake, diabetes/obesity |
| Struvite (infection) | ~5% | Recurrent UTI with urea-splitting bacteria |
| Cystine | <1% | Genetic disorder (cystinuria) |
Knowing the stone type matters — it directly drives prevention strategy. This is why stone analysis (sending the passed or removed stone for laboratory testing) is part of comprehensive stone management.
Symptoms of Kidney Stones
The classic presentation is renal colic — severe, sudden-onset pain that often comes in waves. However, stones can also be silent and detected incidentally on scans for other reasons.
Renal Colic — The Classic Presentation
| Feature | Detail |
|---|---|
| Pain location | Flank (loin) radiating to the groin or testicle |
| Pain character | Severe, colicky, comes in waves |
| Pain trigger | Often sudden onset; not relieved by changing position |
| Associated symptoms | Nausea, vomiting, restlessness, sweating |
| Urinary symptoms | Frequency, urgency, blood in urine (visible or microscopic) |
Patients often describe renal colic as the most severe pain they have ever experienced — frequently compared to childbirth.
Other Stone Symptoms
- Visible blood in the urine (haematuria) — particularly with bladder stones or stones moving in the ureter
- Frequency and urgency — particularly with stones near the bladder
- Recurrent urinary tract infections
- Persistent dull flank pain — with chronic obstruction
- No symptoms at all — many small kidney stones are detected incidentally on CT scans for other indications
When to Seek Urgent Help (A&E or 999)
Some stone presentations are urological emergencies. Attend A&E immediately if you have:
- Severe pain that is not controlled by pain relief
- Fever or rigors with flank pain — suggests infected obstruction (urosepsis)
- Inability to pass urine
- Persistent vomiting
- Signs of sepsis — confusion, rapid heart rate, low blood pressure
- Reduced urine output with kidney impairment
Stones with infection or obstruction can cause kidney damage and life-threatening sepsis within hours. This is not a situation for private elective referral — go straight to A&E.
For elective stone management, recurrent stone disease, prevention work-up, and post-acute follow-up, private consultation is the right route.
Risk Factors
| Risk Factor | Why It Matters |
|---|---|
| Inadequate fluid intake | Concentrated urine encourages crystal formation |
| High-salt diet | Increases urinary calcium excretion |
| High animal protein intake | Increases urinary calcium and uric acid; lowers urinary citrate |
| Obesity and metabolic syndrome | Increases uric acid stones and overall stone risk |
| Family history | First-degree relatives have approximately double the risk |
| Previous stone | The strongest predictor — ~50% recurrence in 5–10 years without prevention |
| Anatomical abnormalities | Pelvi-ureteric junction obstruction, horseshoe kidney, medullary sponge kidney |
| Recurrent UTIs | Particularly risk for struvite stones |
| Hyperparathyroidism | Causes hypercalciuria; should always be screened in recurrent stoners |
| Inflammatory bowel disease | Increases oxalate absorption (enteric hyperoxaluria) |
| Hot climate / occupational heat exposure | Increases dehydration |
| Certain medications | Topiramate, indinavir, calcium-vitamin D supplements, sulphonamides |
The most important takeaway: about 50% of people who form one kidney stone will form another within 5–10 years if no preventive measures are taken. Prevention is the most underutilised intervention in stone disease.
How Kidney Stones Are Diagnosed
1. Clinical Assessment
History, examination, and review of any previous imaging or stone history.
2. Urine Tests
- Urine dipstick (looking for blood, infection)
- Urine culture (to rule out infection)
- Urine pH (helps predict stone type)
3. Blood Tests
- Kidney function (urea, creatinine, eGFR)
- Calcium, uric acid, parathyroid hormone (PTH)
- Glucose / HbA1c if diabetes is suspected
- Inflammatory markers if infection is a concern
4. CT KUB (Kidneys, Ureters, Bladder)
A non-contrast CT scan is the single most accurate test for kidney stones. It:
- Detects stones as small as 1–2 mm
- Identifies stone size, position, and density (Hounsfield units)
- Quantifies the degree of obstruction
- Identifies anatomical variants relevant to surgical planning
- Excludes other causes of flank pain
CT KUB is preferred over ultrasound or X-ray because it is significantly more sensitive and provides the detail needed for treatment decisions.
5. Stone Density (Hounsfield Units)
Stone density on CT predicts how well a stone will respond to ESWL — denser stones (>1000 HU) often need ureteroscopy rather than ESWL.
6. Stone Analysis
If a stone is passed or removed, sending it for chemical analysis is essential — it directly drives prevention strategy. This is one of the most underused investigations in NHS stone care.
Treatment Options
The right treatment depends on stone size, location, density, your symptoms, and any anatomical considerations.
| Treatment | Best Suited For | Pros | Cons |
|---|---|---|---|
| Conservative management | Stones <5 mm, no infection or obstruction | Avoids surgery; many pass spontaneously | Pain, may take weeks |
| Medical expulsive therapy | Distal ureteric stones 5–10 mm | Improves passage rate; avoids surgery | Off-label use of alpha-blockers |
| Ureteroscopy (URS) with laser | Most ureteric stones; renal stones up to 2 cm | High clearance rate; same-day or one-night stay | Stent often needed; mild discomfort |
| ESWL (shock wave lithotripsy) | Suitable renal and upper ureteric stones <2 cm | Non-invasive; outpatient; no anaesthetic | Lower clearance rate; not suitable for hard stones; multiple sessions sometimes needed |
| Ureteric stent (alone) | Acute relief of obstruction; pre-treatment | Quick decompression | Temporary measure; symptomatic |
| Laparoscopic endopyelotomy | Selected pelvi-ureteric junction obstruction | Definitive correction of obstruction | Specialist procedure |
| PCNL (referred) | Stones >2 cm, staghorn calculi, complex anatomy | Highest clearance rate for large stones | Specialist availability; longer recovery |
The European Association of Urology (EAU) and BAUS guidelines recommend a stone-size-and-location-specific approach: ESWL or URS for most ≤2 cm stones, PCNL for larger stones, and conservative management for small ureteric stones.
Conservative Management
For small stones (<5 mm) without infection or significant obstruction, observation with adequate analgesia and hydration is appropriate. Around 80% of stones <5 mm and around 50% of stones 5–10 mm pass spontaneously, usually within 4–6 weeks.
Practical management:
- Drink enough fluid to keep urine pale (typically 2.5–3 litres per day)
- Strain urine to catch the stone for analysis
- Pain relief — paracetamol, NSAIDs (where not contraindicated), occasionally stronger
- Medical expulsive therapy with an alpha-blocker (tamsulosin) for distal ureteric stones — improves passage rate by around 20%
- Imaging review at 4–6 weeks to confirm passage
If the stone has not passed by 4–6 weeks, persists with symptoms, causes obstruction or infection, or fails to progress on imaging, active treatment is recommended.
Ureteroscopy (URS) with Laser Stone Fragmentation
Ureteroscopy is the most commonly used active treatment for stones in modern UK practice. A small, flexible (or rigid for lower ureter) endoscope is passed via the bladder up the ureter to the stone, which is then fragmented with a holmium laser and the fragments removed or allowed to flush out.
What to Expect
| Anaesthetic | General |
| Operative time | 30–60 minutes |
| Hospital stay | Day-case or one night |
| Stent | Usually placed for 1–2 weeks afterwards |
| Return to driving | 1 week |
| Return to desk work | 3–7 days |
| Return to physical activity | 2 weeks |
| Stone clearance rate | 85–95% in suitable cases |
URS is suitable for the majority of ureteric stones and for renal stones up to around 2 cm.
Ureteric Stents
A stent is a soft plastic tube placed temporarily between the kidney and bladder to ensure urine drains while any swelling settles. Stents are usually placed at the end of URS and removed 1–2 weeks later as a quick outpatient procedure.
Stent symptoms — frequency, urgency, mild pain, occasional blood in the urine — are common and resolve once the stent is removed. Most patients tolerate stents well, but if symptoms are severe, alternatives such as alpha-blocker therapy can help.
Extracorporeal Shock Wave Lithotripsy (ESWL)
ESWL is a non-invasive treatment that uses focused shock waves from outside the body to break stones into small fragments, which then pass naturally in the urine. It is performed under sedation or simple analgesia rather than general anaesthetic, on an outpatient basis.
When ESWL Is the Right Choice
- Renal stones up to around 2 cm
- Selected upper ureteric stones
- Stones of moderate density (typically <1000 HU on CT)
- Patients preferring to avoid endoscopic surgery
When ESWL Is Less Suitable
- Very dense stones (>1000 HU) — fragmentation often poor
- Lower pole renal stones with a steep infundibulopelvic angle — fragments don’t clear well
- Lower ureteric stones — URS is more effective
- Pregnancy
- Active urinary infection
- Coagulopathy
- Significant obesity (focusing the shock waves becomes difficult)
- Aortic aneurysm in the path of treatment
Stone clearance rates with ESWL typically range from 50–80%, depending on stone size, density, and location — generally lower than ureteroscopy. Multiple ESWL sessions are sometimes needed.
Laparoscopic Endopyelotomy
For selected patients with pelvi-ureteric junction (PUJ) obstruction — a narrowing where the kidney joins the ureter, often associated with recurrent stones or pain — laparoscopic endopyelotomy or pyeloplasty corrects the underlying obstruction. This is specialist surgery for a specific anatomical problem and is typically combined with stone removal in suitable cases.
Metabolic Stone Work-Up and Prevention
This is the most important and most underused part of stone care. Prevention strategies can reduce recurrence risk by 50% or more, yet standard NHS care often misses them because they require a structured outpatient workflow.
Every stone former should receive basic assessment and stone analysis where a specimen is available. Patients at higher risk of recurrence — including recurrent stone formers and those with particular stone types or medical risk factors — may benefit from more detailed metabolic evaluation, including 24-hour urine testing.
Who Should Have a Metabolic Work-Up?
- Anyone with two or more stones
- Recurrent stones in a single kidney
- Children with stones (always)
- Family history of stones
- Stones in someone with known metabolic disease (gout, hyperparathyroidism, IBD)
- Single stones in selected high-motivation patients
What a Metabolic Work-Up Involves
| Investigation | What It Shows |
|---|---|
| 24-hour urine collection | Calcium, oxalate, uric acid, citrate, sodium, magnesium, volume, pH, creatinine |
| Stone composition analysis | Direct identification of stone type — drives prevention strategy |
| Blood tests | Calcium, phosphate, parathyroid hormone (PTH), uric acid, kidney function, vitamin D |
| Urinalysis | pH, infection, cystine screening |
Personalised Prevention Advice
Based on the work-up findings, prevention is tailored to your specific stone type and metabolic profile. Common interventions include:
- Fluid prescription — aim for >2.5 litres per day, often more in summer or for active people
- Sodium restriction — typically <2.3 g sodium per day; reduces urinary calcium
- Animal protein moderation — reduces calcium and uric acid stones
- Citrate supplementation — potassium citrate or lemon juice for low urinary citrate
- Calcium intake guidance — paradoxically, normal dietary calcium reduces stone risk; calcium supplements can increase risk
- Oxalate moderation — for hyperoxaluria; spinach, rhubarb, nuts, beetroot
- Allopurinol — for some uric acid stones or hyperuricaemia
- Thiazide diuretic — for idiopathic hypercalciuria
- Treatment of underlying condition — hyperparathyroidism, gout, IBD
What Difference Does Prevention Make?
Published evidence consistently shows that structured prevention can substantially reduce the likelihood of further stones, particularly when advice and medication are matched to the patient’s stone type and metabolic abnormalities. The single biggest intervention is increased fluid intake — but specific dietary or pharmacological measures matched to your metabolic profile can substantially improve on that.
For more detailed advice, read my evidence-based guide to preventing kidney stones.
Locations
Consultations are available at any of Mr Haldar’s clinic sites:
| Location | County |
|---|---|
| Chiltern Hospital, Great Missenden | Buckinghamshire |
| The Clementine Churchill Hospital, Harrow | North-West London |
| GenesisCare, Windsor | Berkshire |
| Shelburne Hospital, High Wycombe | Buckinghamshire |
| Beaconsfield Clinic | Buckinghamshire |
Procedures
| Procedure | Locations |
|---|---|
| CT KUB | Chiltern, Clementine Churchill, Princess Margaret, GenesisCare |
| Ureteroscopy with laser | Chiltern, Clementine Churchill, Princess Margaret |
| ESWL | Selected sites (referred to specialist ESWL centre) |
| Stent insertion / removal | Chiltern, Clementine Churchill, Princess Margaret |
| Laparoscopic endopyelotomy | Chiltern, Clementine Churchill, Princess Margaret |
| PCNL | Referred to specialist PCNL centre |
The catchment includes south Oxfordshire (Henley, Thame, Wallingford), Buckinghamshire, Berkshire and North West London.
Frequently Asked Questions
Will my kidney stone pass on its own?
It depends on size and location. Around 80% of stones smaller than 5 mm pass spontaneously, around 50% of stones 5–10 mm, and stones above 10 mm rarely pass without treatment. Distal ureteric stones pass more reliably than upper ureteric stones. A CT KUB scan accurately determines size and likelihood of spontaneous passage.
How long does it take for a kidney stone to pass?
Stones <5 mm typically pass within 4 weeks if they are going to. Stones 5–10 mm may take 6 weeks or longer. If the stone has not passed by 4–6 weeks despite adequate hydration, or if symptoms or obstruction worsen, active treatment is recommended.
What’s the best treatment for kidney stones?
There is no single “best” treatment — it depends on stone size, location, density, your anatomy, and your preferences. Ureteroscopy with laser is the most commonly used modern treatment, with stone clearance rates of 85–95%. ESWL is non-invasive and useful for selected stones, but with lower clearance rates. PCNL is needed for stones above 2 cm or staghorn stones — Mr Haldar refers these patients to specialist colleagues.
Is shock wave lithotripsy painful?
ESWL is generally well-tolerated under sedation. Most patients describe it as a tapping or thumping sensation. Some discomfort may occur during and after the procedure, and bruising is occasionally seen. Stronger analgesia is sometimes needed if shock waves need to be intense.
Why do I need a stent after ureteroscopy?
A stent ensures urine drains from the kidney while any swelling from the procedure settles. Stents are usually left for 1–2 weeks. They can cause mild urinary symptoms (frequency, urgency, occasional pain or blood in the urine), but these resolve once the stent is removed. Stent removal is a quick outpatient procedure.
Will I get more stones?
Without preventive measures, around 50% of stone formers will form another stone within 5–10 years. With structured metabolic work-up and personalised prevention, recurrence risk can be reduced by 50% or more. Mr Haldar offers a full metabolic work-up — 24-hour urine, blood tests, stone analysis, and personalised prevention advice — for recurrent stone formers.
How much water should I drink?
For stone prevention, aim for at least 2.5 litres of urine output per day — typically requiring 3 litres or more of fluid intake, more in hot weather or with exercise. The simplest test is urine colour: if your urine is pale yellow throughout the day, your fluid intake is probably adequate.
Please read my full guide on preventing kidney stones
Do calcium supplements cause kidney stones?
Calcium supplements taken away from meals can increase the risk of calcium oxalate stones. However, dietary calcium with meals reduces stone risk by binding oxalate in the gut. Don’t avoid calcium-rich foods if you have stones — but discuss supplements with your doctor.
Can I prevent stones by avoiding certain foods?
Yes, but it depends on your stone type. Calcium oxalate stones benefit from moderating high-oxalate foods (spinach, rhubarb, nuts, beetroot, dark chocolate). Uric acid stones benefit from reducing red meat, organ meats, and shellfish. Generic dietary advice without knowing your stone type is often unhelpful — this is why metabolic work-up matters.
What if my stone is causing an infection?
A stone with an infection is a urological emergency. The combination of obstruction and infection (urosepsis) can cause life-threatening sepsis and rapid kidney damage. Attend A&E immediately if you have flank pain with fever, rigors, vomiting, or signs of sepsis. NHS emergency care is the right pathway for this — not private elective referral.
When does Mr Haldar refer for PCNL?
For stones larger than around 2 cm or staghorn calculi, percutaneous nephrolithotomy (PCNL) is the most effective treatment. PCNL is highly specialised surgery requiring a high-volume team, so Mr Haldar refers these patients to specialist PCNL colleagues — ensuring the best technique for the largest stones rather than a compromise procedure.
How quickly can I be seen?
Most patients are seen for consultation within 1–2 weeks. We usually arrange a CT KUB within a few days. For urgent or recurrent stone problems, faster appointments are often available — please mention urgency when booking.
Do you accept private medical insurance?
Yes. Mr Haldar is recognised by major UK private health insurers, including BUPA, AXA Health, Aviva, Cigna, Vitality Health, WPA, and Standard Life. Most insurers cover consultation, CT scans, surgical fees, and follow-up, subject to your policy terms. See the Fees and Insurance page for details.
Why Choose Mr Neil Haldar?
- 20+ years’ experience in stone disease
- Comprehensive elective stone service — URS, ESWL, stent management, laparoscopic endopyelotomy
- Full metabolic work-up and prevention — 24-hour urine, stone analysis, personalised dietary and medical advice (the most under-used and most effective part of stone care)
- Honest scope of practice — refers PCNL to specialist colleagues to ensure best technique for the largest stones
- Continuity of care from initial diagnosis through treatment to long-term prevention
- Same-week consultation with rapid CT KUB
- Trusted for second opinions and recurrent stone disease
- Private clinics across London, Buckinghamshire, Berkshire, and Oxfordshire
- Recognised by major UK private health insurers
Useful Resources
Related kidney stone guides
Kidney Stones: Symptoms, Causes, Diagnosis and Modern Treatment
How to Prevent Kidney Stones: An Evidence-Based Guide to Diet, Fluids, Tests and Treatment
Blood in Urine: When Is It Serious?
Recurrent urinary tract infections.
Book a Consultation
If you have a known kidney stone, recurrent stone disease, or want a structured plan to prevent further stones, Mr Haldar would be pleased to help.
Reminder: if you are currently in severe pain, vomiting, feverish, or unable to pass urine — please attend A&E or call 999. Stones with infection or obstruction can cause kidney damage within hours.
Related Reading
Mr Neil Haldar, MBBS MD FRCS (Urol). Consultant Urological Surgeon, Buckinghamshire Healthcare NHS Trust. GMC No: 3683914.
