Pyelonephritis

Pyelonephritis is an inflammatory infection of the upper urinary tract involving the renal parenchyma and renal pelvis, most frequently triggered by bacteria ascending from the lower urinary tract

Pyelonephritis is an inflammatory infection of the upper urinary tract involving the renal parenchyma and renal pelvis, most frequently triggered by bacteria ascending from the lower urinary tract Pathophysiologically, uropathogens—predominantly gram-negative bacilli such as *Escherichia coli*—invade and incite an acute inflammatory response within the renal interstitium and tubules

While it can occur across all demographics, it disproportionately affects females, pregnant individuals, and patients with urinary tract anomalies, immunosuppression, or bladder outflow obstruction

While it can occur across all demographics, it disproportionately affects females, pregnant individuals, and patients with urinary tract anomalies, immunosuppression, or bladder outflow obstruction

Pathophysiologically, uropathogens—predominantly gram-negative bacilli such as *Escherichia coli*—invade and incite an acute inflammatory response within the renal interstitium and tubules

Defining clinical features typically include systemic signs such as fever, rigors, nausea, and vomiting, alongside localized manifestations including flank pain, costovertebral angle tenderness, and pyuria

Defining clinical features typically include systemic signs such as fever, rigors, nausea, and vomiting, alongside localized manifestations including flank pain, costovertebral angle tenderness, and pyuria