Kidney Stones and Strain

A urinary stone becomes clinically significant when it obstructs urine flow, usually in the ureter. The blockage raises pressure above the stone and triggers ureteral smooth-muscle spasm, producing severe flank pain that often radiates toward the lower abdomen or groin. Because the ureter contracts around the obstruction, a patient with renal colic commonly shifts position repeatedly rather than lying still. Nausea and vomiting reflect the intensity of the visceral pain response. Hematuria is common because the stone irritates the urinary tract lining, but its absence does not exclude a stone. The more dangerous combination is obstruction plus infection: bacteria trapped behind a blocked ureter can progress rapidly to pyelonephritis, sepsis, and loss of renal function. Fever is not an expected feature of uncomplicated renal colic. Stones are common and frequently recur. In North America, approximately 12% of men and 10% of women develop kidney stones, and 30% to 50% of patients have another symptomatic episode within 10 years of a first stone. The immediate episode therefore matters twice: the nurse must recognize obstruction now and help the patient prevent another...