Renal artery stenosis (RAS) is one of the most common causes of secondary hypertension. Atherosclerosis, multiple aortitis and myofibrillar dysplasia (FMD) are the common causes of RAS. It is higher in men than in women. Atherosclerotic stenosis of the renal arteries is a progressive disease. Renal artery occlusion is more likely to occur in patients with severe stenosis, combined with diabetes mellitus or severe hypertension. (1) Renal artery stenosis causes (1) renal vascular hypertension is the 2nd leading cause of secondary hypertension; (2) end-stage renal disease (ESRD); (3) renal atrophy renal atrophy is a direct consequence of RAS and is associated with the severity and progression of the lesion; (4) recurrent pulmonary edema; (5) increased risk of cardiovascular events; (6) asymptomatic RAS asymptomatic RAS Patients have a poorer prognosis, which correlates with the degree of RAS. One study found that the 4-year survival rate for asymptomatic, severe RAS (≥75%) found incidentally during cardiac catheterization was 57%, compared with 89% for patients with non-severe RAS. 2. The following conditions may suggest the presence of RAS (1) the following manifestations of hypertension: hypertension before the age of 30 years or severe hypertension after the age of 55 years; acute progressive hypertension (sudden and persistent worsening of previously controllable hypertension); recalcitrant hypertension (those who have difficulty achieving target blood pressure when a combination of three antihypertensive drugs, including diuretics, is applied in sufficient doses); malignant hypertension (hypertension combined with acute target organ injury including acute renal failure, acute decompensated congestive heart failure or new onset of optic nerve or other cerebral neuropathy and retinopathy of III-IV). (2) New-onset azotemia or worsening renal function (elevated blood creatinine greater than 50%) when ACEI or ARB drugs are applied; (3) Presence of unexplained renal atrophy or bilateral renal size difference of more than 1.5 cm; (4) Sudden onset of unexplained pulmonary edema. 3, the concomitant relationship between hypertension and renal disease There is a concomitant relationship between the two. Hypertensive disease can cause kidney damage, and the latter further increases blood pressure and makes it difficult to control. Hypertension due to kidney disease is called renal hypertension, mainly caused by renal vascular disease (such as renal artery stenosis) and renal substantive disease (glomerulonephritis, chronic pyelonephritis, polycystic kidney, etc.), which can produce hypertension during the progression of renal disease, and the latter exacerbates the renal lesion to make renal function decompensate, forming a vicious circle.