High blood pressure despite taking antihypertensive drugs may be caused by medication, secondary causes and other reasons. 1. Drugs: Due to the variety of antihypertensive drugs and individual differences, if the drugs taken do not exactly correspond to the patient’s symptoms, the phenomenon of high blood pressure even after taking antihypertensive drugs may occur. For example, in patients with grade 2 or higher hypertension, it is difficult to lower the blood pressure to the normal range if a single antihypertensive drug is used. 2. Secondary causes: If the patient has other diseases such as renal artery stenosis, secondary hypertension may occur, and when the cause of elevated blood pressure cannot be lifted, the phenomenon of high blood pressure despite taking antihypertensive drugs may occur. 3. Other reasons: if the patient’s diet is not regular, overwork, heavy alcohol abuse, etc., may lead to blood pressure is not easy to control, so the phenomenon of taking antihypertensive drugs blood pressure is still high. Therefore, it is recommended to go to the hospital in a timely manner, to clarify the cause of the disease, and then targeted treatment.