Evaluation and Management of Suspected Kidney Stones

Initial Assessment and Diagnostic Workup

The American Urological Association recommends asking about pain characteristics, including location, intensity, radiation, timing, and factors that worsen or improve symptoms, to guide diagnosis and treatment decisions for suspected kidney stones 1
Patients with suspected kidney stones should be assessed for risk factors, including personal or family history of kidney stones, medical conditions such as hyperparathyroidism, renal tubular acidosis, and inflammatory bowel disease, and dietary habits that may increase stone risk 1
Urinalysis should include both dipstick and microscopic evaluation to assess urine pH, presence of blood, signs of infection, and crystal identification, which may be pathognomonic of stone type 1
Serum chemistries should include electrolytes, creatinine, and uric acid to assess kidney function and rule out underlying metabolic disorders 1, 2

Imaging studies, such as ultrasound and non-contrast CT scan, should be used to confirm the diagnosis and guide treatment decisions for suspected kidney stones 3
The American College of Radiology recommends using ultrasound as the first-line imaging modality, especially for pregnant patients, due to its safety and effectiveness 3
Pain control measures, including NSAIDs and opioids, should be used to manage renal colic, with NSAIDs being the preferred first-line treatment 3
Patients with suspected kidney stones should increase fluid intake to promote stone passage and strain urine to catch any passed stones for analysis 4, 3

Stone analysis should be obtained at least once when stone material is available to guide prevention strategies and treatment decisions 1, 3
High-risk or recurrent stone formers should undergo metabolic testing, including 24-hour urine collection, to identify underlying metabolic disorders and guide prevention strategies 1, 3
Prevention strategies, including increasing fluid intake, dietary modifications, and medications, should be tailored to the individual patient's stone type and metabolic profile 1, 5, 4, 3

Patients with suspected kidney stones should seek emergency care if they experience fever, signs of infection, severe uncontrolled pain, vomiting leading to dehydration, or signs of urinary obstruction 2, 3

The American Urological Association recommends advising patients to increase fluid intake to achieve a urine volume of at least 2.5 liters daily 6, 7
Certain beverages, such as coffee, tea, wine, and orange juice, have been associated with a lower risk of stone formation, while sugar-sweetened beverages should be avoided as they may increase stone risk 7
Maintaining normal calcium intake (1,000-1,200 mg/day) from dietary sources rather than supplements is recommended 6, 8
Limiting sodium intake to 2,300 mg daily is advised 6, 7
For calcium oxalate stones, limiting intake of oxalate-rich foods while maintaining normal calcium consumption is recommended 7, 8
Avoiding calcium supplements, which may increase stone risk unlike dietary calcium, is suggested 6, 7

For recurrent stone formers, considering 24-hour urine collection for metabolic evaluation is recommended 6
Restricting dietary calcium is not recommended and may actually increase stone risk by increasing intestinal oxalate absorption 8