Short-acting antihypertensive drugs are generally effective in half an hour, long-acting antihypertensive drugs are generally effective in 2 to 4 hours, and antihypertensive drugs injected into a hypertensive crisis can be effective in a few minutes. Antihypertensive drugs are divided into short-acting antihypertensive drugs and long-acting antihypertensive drugs. Short-acting antihypertensive drugs such as nifedipine, captopril, etc., these drugs can be taken after half an hour to appear very good antihypertensive effect. Long-acting antihypertensive drugs such as amlodipine, chlorosartan, etc., the antihypertensive effect of these drugs is generally reflected in 2~4 hours of taking the drug. Overall, long acting antihypertensive drugs are currently recommended in clinical practice because their antihypertensive effect is more stable, once daily, and compliance is better. It should be noted that if the hypertensive crisis antihypertensive generally need intravenous drip vasodilator drugs, such as nitroglycerin, sodium nitroprusside, etc., so that the effect of antihypertensive effect can be seen within a few minutes. Taking antihypertensive drugs should be selected and used under the guidance of a doctor, do not self-medication.