Which of the following conditions is associated with hypertension emergency?

Hypertensive emergency is characterized by severe elevation in blood pressure, often defined as systolic blood pressure over 180 mmHg or diastolic blood pressure over 120 mmHg, accompanied by acute end-organ damage. Visual changes, specifically retinal hemorrhage, are significant indicators of such end-organ damage. The presence of retinal hemorrhage suggests that the elevated blood pressure has affected the vasculature in the eyes, which is a sign of potential damage to other organs as well.

In contrast, the other options do not depict the critical nature of hypertensive emergencies effectively. Conditions without end organ issues or symptoms typically fall under hypertensive urgency rather than an emergency. A blood pressure reading under 180 systolic does not meet the criteria for a hypertensive emergency, as it does not signify a severe crisis. Mild headache and temporary dizziness may also occur in various situations unrelated to significant end-organ damage, thus not fulfilling the requirements to be classified as a hypertensive emergency.