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A. Calcium-containing stones are the most common (70%).
B. Magnesium-ammonium-phosphate stones, also known as struvite stones, are almost always associated with urinary tract infection by urea-splitting bacteria such as Proteus mirabilis. These are generally responsible for large staghorn calculi stones.
C. Uric acid stones are less common and are radiolucent, making diagnosis by plain films alone difficult.
D. Cystine stones are rare and associated with cystinuria, a rare autosomal recessive hereditary disorder.
A. Renal colic is characterized as severe colicky pain that is intermittent, usually in the flank or lower abdomen. Patients usually can not find a "comfortable position," and the pain often radiates to the testes or groin. A history of previous stones, poor fluid intake, urinary tract infections, or hematuria is common.
B. Obstruction located at the ureteropelvic junction causes pure flank pain, while upper ureteral obstruction causes flank pain that radiates to the groin. Midureteral stones cause lower abdominal pain and may mimic appendicitis or diverticulitis, but without localized point tenderness or guarding. Lower ureteral stones may cause irritative voiding symptoms and scrotal or labial pain.
C. Patients with nephrolithiasis generally complain of nausea and vomiting. They commonly have gross or microscopic hematuria; fever and increased white blood cell count are also possible.
D. Prior episodes of renal colic or a family history of renal stones is often reported.
E. Physical Examination
1. Generally the patient is agitated, diaphoretic, and unable to find a comfortable position. urolithiasis, nephrolithiasis
2. Hypertension and tachycardia are also common.
3. Costovertebral angle tenderness is the classic physical finding; however, minimal abdominal tenderness without guarding, rebound, or rigidity may be present. Right or left lower quadrant tenderness or an enlarged kidney may sometimes be noted.
IV. Laboratory kidney stones Evaluation
A. A kidney stones, urolithiasis, nephrolithiasis urinalysis with microscopic, serum chemistries, BUN, creatinine, complete blood count, and urine culture should be obtained. An elevated white blood cell count may occur, and when it is associated with fever, its presence usually indicates an associated infection. A significant number of white cells in the urine also suggests infection.