Renal hypertension is high blood pressure caused by kidney disease. It can be caused by renal stenosis where the renal arteries narrow, decreasing blood flow to the kidneys, or chronic glomerulonephritis where inflammation damages the glomeruli. This causes increased renal vascular resistance and decreased glomerular filtration, stimulating the renin-angiotensin system which increases blood pressure. Investigations include blood and urine tests, ultrasound, CT scan, and biopsy. Treatments depend on the cause but may include angioplasty, stenting, medications, or controlling blood pressure and protein intake.