Eighty-nine-year-old elderly people after taking antihypertensive drugs low pressure 55mmHg, does not belong to the reasonable range, but for eighty-nine-year-old elderly people is not necessarily abnormal. Need to synthesize the physical condition of the elderly to determine. Due to the elderly blood vessels with age will gradually reduce the elasticity, there will be diastolic blood pressure tends to be low performance, there are some hypertensive patients manifested as simple systolic hypertension, and diastolic blood pressure is normal or lower than normal. If there are no symptoms other than this one after taking antihypertensive drugs, it may be normal. No special treatment is needed. If the elderly people in their eighties or nineties have always had high blood pressure and have not had blood pressure below 55mmHg before taking antihypertensive drugs, the blood pressure is suddenly low after taking the drugs this time and is accompanied by dizziness, fatigue and other symptoms. This situation may be abnormal. If an elderly person in his eighties or nineties has a low blood pressure of 55mmHg after taking antihypertensive medication and is accompanied by other uncomfortable symptoms, he should consult a doctor in a timely manner, and according to the doctor’s clinical experience, choose antihypertensive medication suitable for the elderly to avoid accidents.