The normal range of low pressure is ≥60mmHg and <90mmHg, but it should depend on each patient's situation. If this patient has combined diabetes, hyperlipidemia, coronary heart disease, cerebral hemorrhage, renal insufficiency, etc., it is better to control the low pressure below 85mmHg, so that the blood pressure can ensure the blood supply of the body and protect the heart and cerebral vessels. The patient also has a combination of cerebral infarction, cavernous infarction and other brain blood supply deficiencies, the blood pressure can be appropriately adjusted to about 90mmHg, which can ensure the blood supply to the head. It is important to ensure not only that the low pressure is within the normal range, but also that the high pressure is also within the normal range, i.e., a range of high pressure ≥ 90 mmHg and < 140 mmHg.