What blood pressure reading indicates a hypertensive emergency?

A hypertensive emergency is characterized by an extremely high blood pressure reading that is accompanied by evidence of acute end-organ damage. The threshold for defining a hypertensive emergency is generally recognized as a blood pressure of 180/120 mmHg or higher. This level of blood pressure can lead to serious complications such as stroke, myocardial infarction, or acute renal failure if not addressed promptly and appropriately.

In this context, the reading of 180/120 mmHg signifies a critical situation requiring immediate medical intervention to prevent irreversible damage to target organs. This reading contrasts sharply with lower readings that, while indicative of hypertension, do not reach the level of urgency necessitated by a hypertensive emergency. The other listed values, though elevated, do not meet the criteria for immediate intervention seen in readings at or above the threshold.