How low is blood pressure dangerous?

If

the blood pressure of normal people is measured in a relatively calm environment, and there is no emotional fluctuation, basketball, volleyball, strong tea and coffee, badminton, etc. before measurement, the cuff, sphygmomanometer and heart are placed on the same horizontal line. At this time, the normal value of systolic blood pressure is 90mmHg to 139mmHg, and the normal value of diastolic blood pressure is 60mmHg to 89mmHg. Below this value is called hypotension, which is an abnormal result. And if you don't seek medical help in time, it may cause complications such as syncope, renal insufficiency, angina pectoris and shock, resulting in a decline in quality of life.