Taking antihypertensive drugs can not be detected by blood sampling. Usually after taking antihypertensive drugs, it may lead to abnormalities in blood electrolytes and serum creatinine. In the blood test, the relevant abnormal indicators may be obtained; however, it is not possible to specify whether or not the antihypertensive drugs have been taken. Therefore, the blood test after taking antihypertensive drugs can not be detected. If hypertensive patients need to have blood tests because of their condition, it is recommended that they consult their doctors whether they should stop taking antihypertensive drugs before having blood tests, so as to avoid the influence of antihypertensive drugs on the test results. If the blood test appears abnormal after taking antihypertensive drugs, it is recommended to consult a doctor in time and treat the cause of the disease under the doctor’s guidance.