Why does renal artery stenosis cause high blood pressure?

Regulate bp: The kidneys help regulate the bp. When there is bilateral renal artey stenosis then the sensors in the kidney think the decreased blood flow is from hypotension. The kidney then secretes hormones that cause the body to hold on to salt and water. This raises the bp.The pt becomes hypertensive

See below: The physiology of the kidney is complicated but the short answer is that ras tricks the kidney into thinking it is not getting enough blood. It compensates by releasing hormones that increase systemic blood pressure in an attempt to increase renal blood flow.

Why RAS inc BP?: Why does renal artery stenosis cause high blood pressure. When the stenosis (blockage) gets severe enough the kidney senses the BP is too low and releases the hormone renin into the blood. Renin reacts with a protein made in the liver and generates AI. AI is converted to AII by ACE. AII is the most potent BP raising chemical the body makes. It also stimulates adrenal to make excess aldosterone.