It is very important to maintain a normal range of blood pressure. Blood pressure does not stay constant. For example, high blood pressure (systolic over 140mmHg an diastolic over 90mmHg) can be "stable"... but high blood pressure is a risk factor for heart attack, brain insult, kidneys’ failure, blindness etc.


Low blood pressure (systolic under 90mmHg and diastolic under 60mmHg) can also be "stable" and can cause problems (syncope) but not that serious as high blood pressure.