Kidney stones (renal calculi) are solid crystals formed in the kidneys from minerals and salts.

Types of Kidney Stones:
Calcium stones – Most common (e.g., calcium oxalate, calcium phosphate).

Uric acid stones – Often in people with gout or high-purine diets.

Struvite stones – Linked with chronic urinary tract infections.

Cystine stones – Rare, genetic condition called cystinuria.

Symptoms:
Severe flank pain (radiates to groin)

Nausea and vomiting

Haematuria (blood in urine)

Urinary urgency or frequency

Painful urination (if stone is low in ureter)

Fever and chills (if infection present — medical emergency)

Investigations:
Urinalysis – Haematuria, crystals, infection signs

Blood tests – Renal function, calcium, uric acid

Imaging:

Non-contrast CT scan – Gold standard

Ultrasound – Good for pregnant women or when radiation must be avoided

X-ray KUB – Can detect radio-opaque stones

Treatment:
Depends on stone size, location, and symptoms:

1- Conservative (≤5mm stones)
Hydration (2–3L/day)

Pain relief: NSAIDs (e.g., diclofenac), or opioids if severe

Alpha blockers (e.g., tamsulosin) to aid passage

Monitor for spontaneous passage

2- Interventional
Extracorporeal Shock Wave Lithotripsy (ESWL) – Non-invasive

Ureteroscopy with laser fragmentation – For mid/distal ureter stones

Percutaneous nephrolithotomy (PCNL) – For large (>2 cm) or complex stones

Surgery – Rarely needed now

Prevention:
Increase fluid intake

Dietary modification (low salt, reduce oxalate/purine-rich foods)

Thiazide diuretics (for recurrent calcium stones)

Allopurinol (for uric acid stones)

Reference:

Sorokin I, et al. "Epidemiology of stone disease across the world." World J Urol. 2017;35(9):1301–1320.

NICE Clinical Knowledge Summaries: Renal colic

emins MJ, Matlaga BR. "Management of acute renal colic from ureteral calculus." J Urol. 2009;181(4):1420–1428.

ICE NG118: Renal and ureteric stones: assessment and management (2019)

Fulgham PF, et al. "Clinical effectiveness protocols for imaging in the management of ureteral calculous disease." J Urol. 2013;189(4):1203–1213.

Dr Geranmayeh