Renal diseases and blood pressure dysregulation in acute care: Pathophysiology, clinical patterns.

Blood pressure (BP) abnormalities are clues to make differential diagnosis and prognostic indicators in various renal diseases in the emergency department (ED), arising from and contributing to kidney dysfunction via activation of the renin-angiotensin-aldosterone system, impaired perfusion, volume overload in chronic kidney disease (CKD) patients, inflammatory processes, and traumatic structural injury. This narrative review summarizes BP patterns and pathophysiology across common renal conditions in the ED, including acute kidney injury, CKD, end-stage renal disease, glomerulonephritis, renal trauma, pyelonephritis, renal artery stenosis, nephrolithiasis, renal infarction, and renal tubular acidosis. Distinct BP profiles are observed: Hypotension often indicates prerenal, septic, or shock-associated acute kidney injury, severe infection, trauma, or shock, while hypertension predominates in CKD, end-stage renal disease, and ischemic or obstructive conditions due to renin-angiotensin-aldosterone system activation and sodium retention. Some disorders show variable BP patterns depending on stages, severity, and comorbidities. Overall, BP abnormalities provide valuable diagnostic and management guidance. Recognizing these predictable hemodynamic responses supports timely diagnosis, risk stratification, and targeted ED management.