Renal arteriogram is not painful because local anesthetic is applied during the examination, so there is no discomfort during the whole examination. The renal arteriogram is mainly used to check the degree of stenosis of the renal artery and whether stents need to be placed, and the position and size of the stents can be clarified through this test. Generally speaking, when renal artery stenosis occurs, it will be clinically manifested as refractory hypertension, mainly because renal artery stenosis leads to renal ischemia, which easily activates the renin-angiotensin system, thus manifesting as elevated blood pressure. Stenting can improve the degree of stenosis and improve the blood supply to the kidney: firstly, it can avoid hypertension; secondly, it can improve the blood supply to the kidney to prevent the damage of kidney function and avoid the shrinkage of one kidney and the loss of kidney function.