Hypertension is the medical term for high blood pressure.
Blood pressure is the measure of the force of blood flowing against artery walls.
A blood pressure reading involves two numbers. The first, the systolic, measures pressure on your arteries when you heart is actively pumping. The second, the diastolic, measures the pressure on your arteries when the heart is at rest. Mild hypertension is a diastolic reading of between 90 and 104. A moderate form of hypertension would have a diastolic reading of between 105 and 114, and severe hypertension would be a reading of over 115.