What Is High Blood Pressure?

A blood pressure level of 140/90 mmHg or higher is considered high, according to the National Heart, Lung and Blood Institute. If your blood pressure is between 120/80 mmHg and 139/89 mmHg, then you have pre-hypertension. This means that you don't have high blood pressure now but are likely to develop it in the future. You can take steps to prevent high blood pressure by adopting a healthy lifestyle.