Blood pressure is an important indicator of human vital signs. Normal blood can meet the demands of human life activities and the blood supply to major organs. Too low blood pressure can severely affect human health and even endanger life. Normal blood pressure ranges from 90 to 140 mmHg for systolic and 60 to 90 mmHg for diastolic pressure. A systolic pressure below 90 mmHg and a diastolic pressure below 60 mmHg is considered low blood pressure. Diagnosis should also take into account underlying diseases, clinical symptoms, and other factors.