Severe hypertension is hypertension with diastolic blood pressure greater than or equal to 115 mmHg. When severe hypertension occurs, the body may lose its ability to compensate for hypertensive emergencies, such as cerebral hemorrhage, acute renal insufficiency, and acute heart failure. Severe hypertension should be seen immediately in a regular hospital for intravenous hypotension to lower blood pressure to a reasonable range and prevent target organ damage. Severe hypertension is usually associated with mood swings, sudden drug withdrawal or secondary hypertension. If severe hypertension occurs, the cause should be identified to prevent the recurrence of severe hypertension and aggravation of the condition. Patients with hypertension should take regular oral antihypertensive medications and monitor blood pressure to prevent the occurrence of severe hypertension, which can be life-threatening for patients at any time if it occurs.