A hypertension headache is a headache that occurs when your blood pressure is extremely high. People usually describe it as a severe, sharp pain on both sides of the head. This happens when your blood pressure is 180/120 millimetres of mercury or higher. Below 120/80 mmHg is normal. A GP Glenroy at Magnus Medical can measure your blood pressure to see if it’s too high. Measuring it is the only way to know what it is. Hypertension doesn’t cause symptoms until it’s extremely high. The name for very high blood pressure with symptoms is a hypertensive emergency.