Dizziness and headache after taking antihypertensive drugs may be too low blood pressure, adverse drug reactions or the emergence of cardiovascular and cerebrovascular diseases, to be analyzed on a case-by-case basis. 1. Low blood pressure: some patients, after taking oral medications, especially after changing to new antihypertensive drugs, such as hydrochlorothiazide, metoprolol, etc., there is a sudden decrease in blood pressure, resulting in insufficient perfusion to the brain, heart and other vital organs, causing dizziness and headache. 2. Adverse drug reactions: some drugs such as nifedipine extended-release tablets/controlled-release tablets, amlodipine tablets and other calcium antagonists can act on cerebral blood vessels, which may cause cerebral vasodilatation of the adverse drug reactions, resulting in dizziness and headache symptoms. 3. Cerebrovascular disease: some patients experience dizziness and headache, may be due to atherosclerotic plaque instability, the onset of cerebrovascular disease such as cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage. When there is dizziness and headache after taking antihypertensive drugs, it is recommended to stop the drugs in time, go to the hospital, improve the cranial CT, MRI examination, and then follow the doctor’s instructions to use or stop the drugs.