Renal colic and urinary tract stones
Renal colic is the acute, often severe, colicky flank pain caused by obstruction of the renal tract-usually a urinary calculus in the kidney or ureter. Emergency department (ED) priorities are rapid analgesia, identification of complications (infected obstruction, renal impairment, solitary/transplanted kidney), appropriate imaging to confirm diagnosis and estimate likelihood of passage, and timely urology involvement when indicated (NICE NG118, QS195).
Pathophysiology
Pain arises from increased intraluminal pressure proximal to an obstruction (pelvicalyceal distension), ureteric spasm and local inflammation. Obstruction may be intermittent or persistent; prolonged or bilateral obstruction risks acute kidney injury. An obstructed system with infection is a urological emergency.
Stone types and clinical relevance
Stone analysis, when available, guides secondary prevention and specialist assessment.
History and examination
Typical presentation: sudden severe unilateral flank pain radiating to the lower abdomen, groin, testis or labia; often with nausea/vomiting. Examine for costovertebral angle tenderness and signs of systemic infection.
Red flags that require urgent action:
- Fever, rigors or other sepsis signs
- Hypotension or altered mental state
- Rising serum creatinine or known solitary/transplanted kidney
- Bilateral obstruction
- Intractable vomiting, uncontrolled pain, or inability to tolerate oral intake