Whether diastolic blood pressure of 100 mmHg is dangerous or not is related to the timely control of blood pressure. How to timely treatment to control blood pressure up to standard without target organ damage is not dangerous, on the contrary is dangerous. 1. Diastolic blood pressure of 100 mmHg, timely to the hospital, under the guidance of the doctor reasonable use of antihypertensive drugs, adjust the blood pressure, if the blood pressure gradually decline and reach the standard, generally is not dangerous. Patients can live and work normally, and life expectancy will not be affected. 2. If the persistent systolic blood pressure exceeds 180 mmHg, this situation is more dangerous. Persistent increase in blood pressure can cause target organ damage and complications. For example, atherosclerosis, impaired renal function. In severe cases, it can cause cerebral infarction, cerebral hemorrhage, acute myocardial infarction, renal insufficiency, etc., which is not only harmful to the patient’s health but also life-threatening. If the diastolic blood pressure level is 100 mmHg, it is recommended that the patient should consult the cardiovascular department of a regular hospital.