Find out how you can reduce your risk of heart disease with our free heart risk assessment. Usually hypertension is defined as blood pressure above 140/90, and is considered severe if the pressure is above 180/120. High blood pressure often has no symptoms. Over time, if untreated, it can cause health conditions, such as heart disease and stroke. Eating a healthier diet with less salt, exercising regularly, and taking medications can help lower blood pressure.