A renal arteriogram costs about 3,000 dollars a time, and the main purpose of the renal arteriogram is to rule out renal artery stenosis, and to rule out the possibility of secondary hypertension in patients with high blood pressure, especially in young patients. One of the causes of secondary hypertension is renal artery stenosis. Renal artery stenosis results in inadequate renal perfusion, which leads to the activation of the renin system, which plays a very important role in elevating blood pressure. Therefore, renal artery stenosis is a very important and common cause of secondary hypertension. When it is suspected that elevated blood pressure and renal artery stenosis have a strong relationship, renal arteriography should be performed. Renal arteriography costs 3,000 dollars a time, and the image is relatively clear, which is the gold standard for the diagnosis of renal artery stenosis, but renal arteriography also has certain risks, because the contrast agent needs to be excreted through the kidneys, which may cause kidney damage, which is called contrast-related nephropathy in medicine. Before and after the imaging must pay attention to more hydration, can reduce the incidence of disease.