According to the American College of Cardiology and the American Heart Association, the goal of blood pressure treatment is to attain a blood pressure reading that's less than 130/80 mmHg systolic and less than 80mmHg diastolic. In general, if you have hypertension, it is likely that you will need to be treated for the duration of your life to maintain this target blood pressure.
When you get a high blood pressure reading at the doctor's office, it might be tough for you to understand exactly what impact those numbers can make on your overall health, since high blood pressure has no unusual day-to-day symptoms. But the truth is, having high blood pressure is a serious health risk—it boosts the risks of leading killers such as heart attack and stroke, as well as aneurysms, cognitive decline, and kidney failure. What's more, high blood pressure is a primary or contributing cause of death in more than 1,000 deaths a day in the United States.
In Sweden, blood pressure is often wrongly measured at clinics with the subjects lying down. The differences tend to be small, however: when seated, the systolic blood pressure registers a little lower, and the diastolic a little higher. Trying this on myself, I noted readings of 116/73 averaged over several seated measurements and an average of 119/72 lying down.