Kidney Stones: Symptoms, Causes, Diagnosis and Modern Treatment

By Mr Neil Haldar, Consultant Urological Surgeon

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Kidney stones are hard deposits that form from minerals and salts in the urine. They may remain in the kidney without causing symptoms or move into the ureter—the tube connecting the kidney to the bladder—where they can obstruct urine flow and cause severe pain.

Common symptoms include:

• Sudden, severe pain in the side or back
• Pain spreading towards the lower abdomen, groin, testicle or labia
• Blood in the urine
• Nausea or vomiting
• Urinary urgency or discomfort

Many small stones pass naturally, but others require treatment with shockwave lithotripsy, ureteroscopy and laser fragmentation, or percutaneous nephrolithotomy.

Fever or shivering associated with kidney stone pain may indicate an infected, obstructed kidney and requires emergency medical assessment.

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What are kidney stones?

Kidney stones—also called renal calculi—are solid deposits that form when substances normally dissolved in the urine become sufficiently concentrated to crystallise.

Urine naturally contains minerals and waste products such as calcium, oxalate, phosphate and uric acid. It also contains substances, including citrate, that help prevent crystals from forming. A kidney stone can develop when the balance between these stone-forming and stone-inhibiting substances is disturbed.

Kidney stones vary considerably in size. Some are no larger than a grain of sand, while others grow to several centimetres. Large branching stones known as staghorn calculi can occupy much of the kidney’s internal collecting system.

A stone can remain in the kidney for months or years without causing symptoms. Problems commonly begin when it moves into the ureter. Because the ureter is narrow, a stone may temporarily or persistently obstruct the drainage of urine from the kidney.

Kidney stones are common. Approximately one in 11 people experiences stone symptoms during their lifetime, and stones are also frequently found incidentally on scans performed for unrelated reasons. After someone has formed one stone, the risk of forming another may approach 50% over the following ten years.

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What is the difference between a kidney stone and a ureteric stone?

The terms are sometimes used interchangeably, but they describe the location of the stone:

• A kidney stone is situated within the kidney.
• A ureteric stone has moved from the kidney into the ureter.
• A bladder stone forms or becomes lodged within the bladder and is managed differently.

A stone inside the kidney may cause no symptoms. A stone in the ureter is more likely to obstruct urine flow and cause renal colic.

The stone’s size is important, but location matters as well. A small stone close to the bladder is generally more likely to pass naturally than a similarly sized stone near the kidney.

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What are the different types of kidney stones?

Knowing the composition of a stone can help identify why it formed and how another may be prevented.

Whenever possible, a stone that has been passed or removed should be sent for laboratory analysis.

Calcium oxalate stones

Calcium-based stones account for approximately 60–80% of urinary stones, with calcium oxalate being the most common individual type.

They may be associated with:

• Low urine volume
• High urinary calcium
• High urinary oxalate
• Low urinary citrate
• Excessive salt intake
• Certain bowel conditions or operations
• Genetic susceptibility

Having a calcium stone does not usually mean that a person has consumed too much calcium.

Calcium phosphate stones

Calcium phosphate stones are less common than calcium oxalate stones. They may be associated with unusually alkaline urine and metabolic conditions such as:

• Renal tubular acidosis
• Primary hyperparathyroidism
• Certain urinary infections
• Some medications, including topiramate

Because the preventive approach can differ from that used for other stones, accurate analysis is important.

Uric acid stones

Uric acid stones form particularly readily in persistently acidic urine.

They are more common in people with:

• Gout
• Diabetes or insulin resistance
• Obesity or metabolic syndrome
• High intake of meat and animal protein
• Low urine volume
• Excessive urinary uric acid

Uric acid stones account for approximately 5–10% of stones. Unlike most calcium stones, they may not be visible on an ordinary abdominal X-ray, although they can usually be seen on CT.

Some uric acid stones can be dissolved by making the urine less acidic with prescribed medication.

Struvite or infection stones

Struvite stones form in association with particular bacteria that produce an enzyme called urease. This changes the chemistry of the urine and encourages rapid stone growth.

Infection stones may become large and develop into staghorn calculi. Treatment usually aims to remove as much stone material as possible because remaining fragments can harbour bacteria and contribute to recurrent infection.

Cystine stones

Cystine stones are rare and result from an inherited condition called cystinuria. They often present at a younger age and have a strong tendency to recur.

People with cystinuria usually need specialist long-term management involving:

• Very high fluid intake
• Dietary modification
• Urinary alkalinisation
• Periodic imaging
• Medication in selected cases

Cystine stones account for approximately 1% of urinary stones.

Drug-related stones

A small number of medications can cause stones either by crystallising within the urine or by changing urine chemistry. Examples include:

• Topiramate
• Zonisamide
• Triamterene
• Some HIV protease inhibitors
• Certain antiviral drugs

Medication should not be stopped without discussing it with the clinician who prescribed it.

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Why do kidney stones form?

Most stones result from a combination of factors rather than one single cause.

Not drinking enough fluid

Low urine volume is one of the most important modifiable risk factors.

When less urine is produced, calcium, oxalate, uric acid and other substances become more concentrated and are more likely to crystallise.

People may be particularly vulnerable if they:

• Work in a hot environment
• Exercise heavily
• Sweat frequently
• Travel regularly to hot countries
• Find it difficult to drink during the working day

Too much salt

A high-salt diet increases the amount of calcium excreted into the urine and can increase the risk of calcium stone formation.

Salt is not limited to what is added at the table. Much of the salt in a typical diet comes from processed meat, ready meals, sauces, bread, soups, takeaway food and savoury snacks.

BAUS dietary guidance advises limiting salt intake to approximately 5–6g daily.

Excessive animal protein

Large amounts of red meat, processed meat, organ meat and some fish can:

• Increase uric acid production
• Make the urine more acidic
• Reduce urinary citrate
• Encourage calcium and uric acid stone formation

This does not mean that everyone with a stone must become vegetarian. Moderate portions and a balanced diet are usually more appropriate than indiscriminate restriction.

Dietary oxalate

Oxalate is present in foods including:

• Spinach
• Rhubarb
• Beetroot
• Nuts and nut products
• Sesame seeds
• Chocolate and cocoa
• Strong or excessive black tea
• Some soya products

Most people do not need to eliminate all oxalate-containing foods. Selective restriction is more appropriate in those with calcium oxalate stones and evidence of raised urinary oxalate.

BAUS advises moderation rather than complete exclusion for most stone formers.

Abnormal calcium metabolism

Some people excrete an excessive amount of calcium into their urine, a condition called hypercalciuria.

This does not necessarily mean that the calcium level in the blood is high. Hypercalciuria may be influenced by genetics, salt intake, hormonal conditions or other metabolic factors.

Bowel disease or bowel surgery

Inflammatory bowel disease, chronic diarrhoea, bowel resection and some forms of bariatric surgery can increase intestinal oxalate absorption.

This is known as enteric hyperoxaluria and can substantially increase the risk of calcium oxalate stones.

Anatomical abnormalities

Conditions that slow urinary drainage may increase the likelihood of crystals remaining in the kidney and growing into stones. Examples include:

• Horseshoe kidney
• Pelviureteric junction obstruction
• Calyceal diverticulum
• Medullary sponge kidney
• Other causes of urinary stasis

Family history

Kidney stones often run in families. A family history may reflect inherited differences in urinary chemistry, shared dietary habits or both.

Recurrent stones beginning in childhood or early adulthood may require investigation for an inherited metabolic condition.

Medical conditions

Conditions associated with stone formation include:

• Primary hyperparathyroidism
• Gout
• Diabetes
• Obesity and metabolic syndrome
• Renal tubular acidosis
• Recurrent urinary infection
• Chronic bowel disease

Identifying and treating an underlying condition can be just as important as removing the stone itself.

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Should people with calcium stones avoid calcium?

This is one of the most common misconceptions about kidney stones.

In most patients, normal calcium intake from food should be maintained. Reducing dietary calcium excessively can allow more oxalate to be absorbed from the bowel. The additional oxalate is then excreted into the urine, potentially increasing the risk of calcium oxalate stones.

Food sources of calcium include:

• Milk
• Yoghurt
• Cheese
• Calcium-fortified alternatives
• Some green vegetables

Calcium supplements are different from dietary calcium and should be taken only when clinically indicated. The dose and timing may matter.

In patients with enteric hyperoxaluria, calcium taken with meals may sometimes be recommended because it binds oxalate inside the intestine and reduces its absorption.

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What are the symptoms of a kidney stone?

Renal colic

The classic symptom is renal colic: sudden, severe pain caused by a stone obstructing the ureter.

The pain usually begins in the flank or side of the back and may spread towards the:

• Lower abdomen
• Groin
• Testicle
• Tip of the penis
• Labia

Pain often comes in waves as the ureter contracts around the stone. Patients are commonly restless and unable to find a comfortable position.

This differs from many muscular or abdominal conditions, in which remaining still may reduce discomfort.

Blood in the urine

A stone can irritate the lining of the urinary tract and cause:

• Visible red, pink or brown urine
• Microscopic blood detected only on a urine test

The absence of blood does not completely exclude a stone.

Visible blood in the urine should not automatically be attributed to a kidney stone without appropriate assessment, particularly in older patients or those with risk factors for urinary tract cancer.

Nausea and vomiting

Severe renal colic often causes nausea or vomiting because pain signals from the kidney and ureter interact with nerves supplying the gastrointestinal tract.

Persistent vomiting can lead to dehydration and may make oral pain relief ineffective.

Urinary symptoms

When a stone reaches the lower end of the ureter near the bladder, it may cause:

• Urinary urgency
• Increased frequency
• Discomfort when passing urine
• A persistent sensation of needing to empty the bladder

These symptoms can resemble a urinary infection.

No symptoms at all

Many kidney stones cause no symptoms and are discovered during an ultrasound or CT scan performed for another reason.

An incidental stone does not always require treatment. Management depends on its size, position, growth, the patient’s anatomy and the likelihood of future problems.

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When is a kidney stone an emergency?

A stone obstructing an infected kidney is a urological emergency.

Urine trapped above the obstruction may become infected, allowing bacteria to enter the bloodstream and cause sepsis. The kidney must usually be drained urgently rather than waiting for antibiotics alone to resolve the problem.

Seek urgent medical attention if suspected kidney stone pain is accompanied by:

• Fever
• Shivering or rigors
• Feeling faint, confused or severely unwell
• Persistent vomiting
• Inability to keep fluids or medication down
• Pain that remains severe despite pain relief
• Reduced urine output or inability to pass urine
• Known kidney impairment
• A single functioning kidney
• A transplanted kidney
• Pregnancy

Emergency drainage may also be required if obstruction is causing significant deterioration in kidney function or if pain cannot be adequately controlled.

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How are kidney stones diagnosed?

The diagnosis is based on symptoms, examination, urine and blood tests, and imaging.

CT KUB

For most adults with suspected renal colic, the preferred investigation is a low-dose non-contrast CT scan of the kidneys, ureters and bladder, commonly called a CT KUB.

It can show:

• Whether a stone is present
• Its exact size
• Its position
• Whether the kidney is obstructed
• Whether additional stones are present
• Features that may influence treatment success

NICE recommends urgent low-dose non-contrast CT within 24 hours for adults with suspected renal colic, unless another form of imaging is more appropriate.

Ultrasound

Ultrasound avoids radiation and is normally the first investigation in:

• Pregnancy
• Children and young people

It is also useful for follow-up and can identify swelling of the kidney, known as hydronephrosis.

However, ultrasound may not detect every small ureteric stone, and further imaging is sometimes required if symptoms persist or the diagnosis remains uncertain.

Abdominal X-ray

Some calcium-containing stones can be seen on a plain X-ray, but uric acid stones are usually not visible.

X-rays are less sensitive than CT for initial diagnosis but can be useful when monitoring a known stone that is clearly radiopaque.

Urine tests

Urine may be tested for:

• Blood
• White blood cells
• Nitrites
• Acidity or alkalinity
• Crystals

A urine sample may be sent for culture if infection is suspected.

Blood tests

Blood tests may assess:

• Kidney function
• Signs of infection
• Calcium
• Uric acid
• Other metabolic abnormalities

A high blood calcium level may lead to further investigation for conditions such as hyperparathyroidism.

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Do all kidney stones need treatment?

No. The decision depends on:

• Stone size
• Stone location
• Symptoms
• Degree of obstruction
• Kidney function
• Evidence of infection
• Anatomical factors
• Stone composition
• Previous episodes
• The patient’s occupation, travel and preferences

A small asymptomatic kidney stone may be monitored. A small ureteric stone may be allowed time to pass. A larger stone, persistent obstruction, recurrent infection or uncontrolled pain may justify active treatment.

Treatment should therefore be personalised rather than determined by stone size alone.

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Can a kidney stone pass naturally?

Many small ureteric stones pass without surgery.

Stones under approximately 5mm have a relatively good chance of passing, particularly when they are situated in the lower ureter near the bladder. The likelihood of spontaneous passage falls as stone size increases.

Conservative management may involve:

• Appropriate pain relief
• Maintaining normal hydration
• Medication for nausea
• A urine strainer to catch the stone
• Follow-up imaging
• An alpha-blocker in selected patients

Patients should not attempt to force a stone through by drinking excessive quantities of water during severe colic. Maintaining hydration is sensible, but forced fluid intake has not been shown reliably to accelerate passage and may worsen discomfort when the ureter is obstructed.

Pain relief for renal colic

Non-steroidal anti-inflammatory drugs, commonly called NSAIDs, are generally the preferred first-line pain treatment when they are safe for the individual patient.

They may not be suitable for everyone, particularly those with:

• Kidney impairment
• Previous stomach ulcers
• Certain cardiovascular conditions
• Some forms of asthma
• Anticoagulant treatment
• Pregnancy

Alternative pain relief may be required.

Medical expulsive therapy

An alpha-blocker such as tamsulosin may be considered for a stone in the distal ureter measuring less than 10mm. The potential benefit appears greatest for stones measuring approximately 5–10mm.

The medication relaxes smooth muscle in the ureter and may help the stone pass. This approach is known as medical expulsive therapy.

NICE recommends considering alpha-blockers for distal ureteric stones under 10mm.

Why follow-up is important

The disappearance of pain does not always prove that a stone has passed. Occasionally, obstruction persists silently.

Follow-up imaging may therefore be advised to confirm that:

• The stone has passed
• The kidney is draining normally
• Kidney function is not at risk

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Modern treatment options for kidney stones

Shockwave lithotripsy

Shockwave lithotripsy, also called SWL or ESWL, uses focused shockwaves generated outside the body to break a stone into smaller pieces.

The fragments then pass naturally through the urinary tract.

Advantages of shockwave lithotripsy

• No incision
• Usually performed as a day-case procedure
• Often avoids general anaesthesia
• Relatively short recovery
• Effective for appropriately selected stones

Limitations

Success is influenced by:

• Stone size
• Stone location
• Stone density
• Distance between the skin and the stone
• Kidney anatomy
• The patient’s ability to pass the fragments

Hard stones and stones in the lower part of the kidney may be less likely to clear completely. More than one session may be required, and fragments can occasionally obstruct the ureter.

SWL is not usually appropriate during pregnancy or when an untreated urinary infection is present. It also carries a higher bleeding risk in patients taking certain anticoagulant or antiplatelet medications.

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Ureteroscopy and laser stone treatment

During ureteroscopy, a fine telescope is passed through the urethra into the bladder and then into the ureter. No skin incision is normally required.

The stone can be:

• Removed intact with a small basket
• Broken into fragments using a laser
• Reduced to very small particles by laser “dusting”

A flexible ureteroscope can be passed into the kidney to treat renal stones. This is sometimes called flexible ureterorenoscopy or RIRS.

Modern systems commonly use holmium:YAG or thulium fibre lasers.

Advantages

• High stone-clearance rates
• Direct visual treatment of the stone
• Can treat ureteric and renal stones
• Suitable when SWL is unlikely to succeed
• Can treat several stones during one procedure
• May be used when antithrombotic medication cannot safely be interrupted, following individual assessment

Ureteroscopy is classed as a lower-bleeding-risk procedure than SWL or PCNL, although management must still be coordinated with the clinician responsible for anticoagulant or antiplatelet medication.

Possible limitations and side effects

• A general anaesthetic is usually required
• A temporary ureteric stent may be needed
• Infection or bleeding can occur
• The ureter may occasionally be too narrow to access safely at the first procedure
• A second procedure may be required for a large stone burden

A stent is not essential after every uncomplicated ureteroscopy, but it may be advised where there is swelling, ureteric trauma, infection risk, residual fragments or uncertainty about drainage.

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Percutaneous nephrolithotomy

Percutaneous nephrolithotomy, or PCNL, is generally used for larger or more complex kidney stones.

A small tract is created through the skin of the back directly into the kidney. A telescope is passed through this tract so that the stone can be fragmented and removed.

PCNL is commonly considered for:

• Stones larger than approximately 2cm
• Staghorn stones
• Large-volume stone disease
• Stones unsuitable for SWL or flexible ureteroscopy
• Stones that have not cleared after other treatments

Advantages

• Highest stone-clearance rate for large kidney stones
• Removes a greater volume of stone in one procedure
• Effective for complex and staghorn calculi

Limitations

• More invasive than SWL or ureteroscopy
• Requires general anaesthesia
• Carries a greater risk of bleeding
• Usually involves a hospital stay
• Particularly large or complex stones may need staged treatment

BAUS describes PCNL as a treatment that allows larger volumes of stone to be cleared and stones in difficult positions to be treated.

Anticoagulant therapy normally needs careful management before PCNL because it is considered a higher-bleeding-risk procedure.

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Emergency ureteric stent

A ureteric stent is a thin internal tube placed between the kidney and bladder.

It bypasses an obstructing stone and allows urine to drain, but it does not usually remove the stone itself.

Stents may cause:

• Urinary frequency
• Urgency
• Bladder discomfort
• Blood in the urine
• Flank discomfort during urination

These symptoms usually resolve after the stent is removed.

Percutaneous nephrostomy

A nephrostomy is a tube inserted through the skin directly into the kidney.

Like a stent, it drains the obstructed kidney without immediately treating the stone.

A nephrostomy may be preferred depending on:

• The patient’s condition
• The position of the stone
• The anatomy of the urinary tract
• Local expertise
• The urgency of drainage

Where infection is trapped behind an obstructing stone, definitive laser treatment or lithotripsy is usually delayed until drainage has been established and the infection has settled.

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Which kidney stone treatment is best?

There is no single best procedure for every stone.

Shockwave lithotripsy may be favoured when:

• The stone is relatively small
• Its position is suitable
• Its density suggests it will fragment
• The patient would prefer a non-invasive approach
• Anaesthesia is undesirable

Ureteroscopy may be favoured when:

• The stone is in the ureter
• A higher chance of clearance in one procedure is wanted
• SWL has failed
• The stone is hard or poorly positioned for SWL
• Several stones need treatment
• Antithrombotic medication cannot easily be stopped

PCNL may be favoured when:

• The stone is larger than approximately 2cm
• There is a staghorn calculus
• The total stone burden is substantial
• Other treatments are unlikely to provide satisfactory clearance

The final recommendation should take account of both clinical evidence and the patient’s priorities, including recovery time, number of procedures, anaesthetic considerations and tolerance of residual fragments.

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What is a ureteric stent, and will I need one?

A stent is sometimes inserted after ureteroscopy to ensure that urine continues to drain while the ureter recovers.

It may be more likely to be required when:

• The ureter has been stretched or instrumented
• There is residual swelling
• Stone fragments remain
• Infection is a concern
• The procedure has been prolonged
• Kidney drainage is uncertain
• The patient has a single functioning kidney

Stents can be uncomfortable, but they are temporary. The planned date and method of removal should always be made clear.

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How can kidney stones be prevented?

Removing a stone treats the immediate problem. Prevention aims to reduce the likelihood of another one forming.

Drink enough to produce dilute urine

For most stone formers, fluid intake should be sufficient to produce approximately 2–2.5 litres of urine daily. This often requires drinking around 2.5–3 litres of fluid, although needs vary with climate, body size, activity and medical conditions.

Fluid should be spread throughout the day rather than consumed mainly in the evening.

Additional fluid may be needed during:

• Hot weather
• Exercise
• Air travel
• Long operating or working sessions
• Illness causing fever, vomiting or diarrhoea

Water is generally the best choice. Excessive sugary drinks should be avoided.

People with heart failure, advanced kidney disease or another condition requiring fluid restriction should seek individual advice before increasing intake.

Reduce salt

Aim for no more than approximately 5–6g of salt daily.

Practical measures include:

• Avoid adding salt at the table
• Check labels on processed foods
• Reduce ready meals and takeaway meals
• Limit processed meat
• Choose unsalted nuts
• Use herbs, spices, lemon and vinegar for flavour

Reducing salt may lower urinary calcium as well as benefiting blood pressure.

Maintain normal dietary calcium

Do not routinely adopt a low-calcium diet after forming a calcium stone.

Normal calcium from food can bind oxalate in the intestine, reducing the amount absorbed into the bloodstream and later excreted into the urine.

Moderate animal protein

Avoid excessive quantities of red meat, processed meat, organ meat and high-purine seafood.

A balanced diet with greater emphasis on vegetables, fruit, whole grains and plant protein may reduce stone risk and support general metabolic health.

Do not eliminate every high-oxalate food indiscriminately

Oxalate restriction should be proportionate and preferably guided by:

• Stone analysis
• Dietary assessment
• A 24-hour urine test

Patients with high urinary oxalate may benefit from limiting the most concentrated sources and consuming calcium-containing food at the same meal.

Avoid unnecessary high-dose supplements

High-dose vitamin C can increase urinary oxalate in susceptible individuals. Calcium, vitamin D and other supplements should be reviewed if stones are recurrent.

Patients should not stop a medically indicated supplement without professional advice.

Maintain a healthy weight

Obesity, insulin resistance and diabetes are associated particularly with acidic urine and uric acid stones.

Gradual weight loss, regular physical activity and good diabetic control can reduce risk.

Crash dieting and very high-protein diets may worsen stone-forming tendencies.

Increase urinary citrate where appropriate

Citrate binds calcium and helps inhibit crystal growth.

Dietary citrate may be obtained from citrus fruit and drinks containing lemon or lime, although dietary approaches are not equivalent to prescription treatment.

Potassium citrate may be prescribed for:

• Low urinary citrate
• Uric acid stones
• Cystinuria
• Certain calcium stones
• Some forms of renal tubular acidosis

It is not appropriate for every stone type and may require blood-test monitoring.

Targeted medication

Medication should be based on stone analysis and metabolic findings rather than given generically.

Options may include:

• Thiazide-type medication for persistent hypercalciuria
• Potassium citrate for hypocitraturia or urinary alkalinisation
• Allopurinol for selected patients with excessive uric acid production or excretion
• Specialist medication for cystinuria

In uric acid stone disease, correcting persistently acidic urine is often more important than simply lowering the blood uric acid level.

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Who should have a metabolic stone assessment?

Every stone former should usually have basic blood tests, urine testing and stone analysis where a specimen is available.

A more detailed investigation may be appropriate for people with:

• Recurrent stones
• Stones at a young age
• A family history of recurrent stones
• A single functioning kidney
• Bilateral stones
• Multiple stones
• Staghorn or infection stones
• Cystine or uric acid stones
• Bowel disease or previous bowel surgery
• Kidney impairment
• Suspected metabolic disease
• Rapid stone regrowth

A specialist assessment may include one or two 24-hour urine collections measuring:

• Urine volume
• Calcium
• Oxalate
• Citrate
• Uric acid
• Sodium
• Acidity
• Other relevant substances

BAUS recommends 24-hour urine assessment particularly for younger and recurrent or otherwise high-risk stone formers.

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Do kidney stones need long-term follow-up?

Follow-up should be individualised.

It may involve:

• Ultrasound
• Plain X-ray for suitable stones
• Low-dose CT when symptoms recur or treatment is planned
• Repeat blood tests
• Repeat 24-hour urine collections
• Monitoring of preventive medication

Patients with residual fragments, metabolic abnormalities or high-risk stone types generally need closer observation.

CT provides the greatest anatomical detail but involves radiation, so ultrasound or X-ray may be preferred for routine surveillance where appropriate. The EAU recommends reserving CT mainly for symptomatic disease or preoperative planning when lower-radiation imaging is adequate for follow-up.

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When should you see a urologist?

A urological opinion may be helpful if:

• A stone is unlikely to pass naturally
• Pain is persistent or recurrent
• The kidney remains obstructed
• Infection has occurred
• Kidney function is affected
• You have a single functioning kidney
• Stones are recurring
• The stone is increasing in size
• You are uncertain which treatment is most appropriate
• You would like a preventive metabolic assessment

Patients seeking private assessment for kidney stones in Buckinghamshire or the Thames Valley can be evaluated by Mr Neil Haldar, with treatment recommendations based on the stone’s size, location, composition, symptoms and individual circumstances.

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Frequently asked questions about kidney stones

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Key points

Kidney stones are common and can cause some of the most severe pain encountered in clinical practice, but modern treatment is usually highly effective.

Many small ureteric stones pass naturally. Stones that are larger, persistently obstructing, infected or causing uncontrolled symptoms may require shockwave lithotripsy, ureteroscopy with laser treatment or percutaneous nephrolithotomy.

Fever or shivering associated with renal colic may indicate an infected obstructed kidney and should never be ignored.

The most important step after the immediate stone has been treated is to understand why it formed. Appropriate fluid intake, reduced salt consumption, normal dietary calcium, stone analysis and targeted metabolic assessment can significantly improve long-term management.

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This article is intended for general information and does not replace individual medical assessment or advice. Seek urgent medical attention for severe pain associated with fever, shivering, persistent vomiting, reduced urine output or feeling seriously unwell.

Last reviewed: July 2026.