There is no definitive data on how long a low blood pressure of 120mmHg lasts is dangerous, there may or may not be symptoms immediately, and immediate hospitalization is recommended. When diastolic blood pressure (i.e., low pressure) is ≥110mmHg, it is considered severe hypertension, a very critical condition that may cause symptoms such as nosebleeds, blurred vision, dizziness and headache, chest tightness and shortness of breath, and may even lead to serious complications such as cerebral hemorrhage, cerebral infarction, aortic coarctation, heart failure, and other serious complications. Even if the symptoms are not shown immediately, when the diastolic blood pressure rises to 130mmHg, the hypertensive emergency that occurs may even instantly lead to cardiac arrest or death, so the discovery of a low blood pressure of 120mmHg should be immediately sent to the hospital for treatment.