Antihypertensive drugs that dilate both micro-arteries and micro-veins include sodium nitroprusside, prazosin and nitroglycerin. 1. Sodium nitroprusside: it is a kind of fast-acting and short-time-acting vasodilator, which reduces peripheral vascular resistance through vasodilatation and plays a role in lowering blood pressure. When some patients take too much, it is easy to cause the blood pressure to decrease too fast to appear dizziness, sweat, headache and other adverse reactions, and in compensated hypertension, such as arteriovenous shunt or aortic constriction is prohibited to use. 2. Prazosin: It has the effect of dilating arteries and veins, decreasing left ventricular end-diastolic pressure, and reducing cardiac preload and afterload. A small number of patients are prone to headache, vomiting, diarrhea and other adverse reactions after taking, and angina, heart failure, mental illness, children, the elderly and other groups should be used with caution. 3. Nitroglycerin: mainly dilate arterial and venous vascular beds, dilate the veins so that the blood is retained in the periphery, reduce the volume of return blood, left ventricular preload is reduced. At the same time, arterial dilatation reduces afterload. Symptoms such as dizziness, weakness, nausea and vomiting may occur after taking it, and it is contraindicated for those who are allergic to nitro compounds, those with severe anemia, glaucoma, increased intracranial pressure, and those with severe hepatic or renal impairment. The above drugs need to be used under the guidance of a professional doctor, patients allergic to the drug is prohibited, pregnant women, lactating women and other groups of people to use with caution, if there are adverse reactions need to consult a doctor in a timely manner.