Many patients with chronic kidney disease are clinically associated with proteinuria, but their blood pressure is normal, but the nephrologists let patients take antihypertensive drugs, many patients are puzzled by this: my blood pressure is normal, why do I use antihypertensive drugs? Usually the antihypertensive drugs prescribed by doctors for patients with proteinuria are ACEI preparations, such as captopril, benazepril, perindopril, fosinopril, etc.; or ARB preparations, such as crosartan, irbesartan, valsartan, candesartan, etc. These drugs are RAAS blockers, which can also reduce proteinuria and have some protective effects on the kidney, in addition to their antihypertensive effects. Their protective effects on the kidney are as follows: obviously dilate the glomerular efferent artery, reduce intra-glomerular pressure, reduce the permeability of glomerular capillaries to proteinuria thus reducing proteinuria, also block renal cell fibrous proliferation and cell hypertrophic proliferation, reduce extracellular matrix deposition, inhibit the reaction of interstitial inflammatory cells, and antioxidant effects, as well as inhibit sympathetic nerve activity, inhibit endothelin, improve Glucose and fat metabolism disorders and other effects. Therefore, the purpose of doctors to let some patients with chronic kidney disease proteinuria take ACEI or ARB preparations is mainly to reduce proteinuria, protect renal function and delay the progression of renal failure through the above-mentioned effects, and not only to lower blood pressure. Of course, for patients with proteinuria accompanied by hypertension, it can be said that medicine can be used for both purposes, killing two birds with one stone, but for patients with chronic kidney disease proteinuria with normal blood pressure, such drugs can also be applied. Zhang Yu, Department of Nephrology, Xiyuan Hospital, Chinese Academy of Traditional Chinese Medicine It should be noted that such antihypertensive drugs as ACEI or ARB must be taken under the specific guidance of a nephrologist, and attention should be paid to observing the changes in renal function glomerular filtration rate and blood potassium, and adjusting the dosage of medication at any time. Patients in the process of taking medication, need to pay attention to the usual get up or sit up is to move slowly to prevent postural hypotension, in addition, if there are obvious symptoms of dizziness and lightheadedness after taking, measured blood pressure is lower than 90/60mmHg, can consider reducing the dose or stop using.