What exactly is blood pressure? Put simply, it is the force with which blood is propelled through your arteries. Unlike a river, which flows continuously downstream, blood flow is pulsatile, with ebb and flow driven by pumping heart muscle. Heart muscle squeezes forcefully, propelling blood forward (systolic pressure). The heart then relaxes and flow ebbs momentarily (diastolic pressur). This cycle repeats itself 60 or so times each minute, every time your heart beats.

Normally, arteries are flexible and "give" with pulsatile blood flow. When there is reduced flexibility or stiffness of arteries, vessels are less able to expand with bursts of flow and pressure increases. This is common in arteries lined with semi-rigid atherosclerotic plaque (often appropriately called "hardening of the arteries") or with any condition that simply adds rigidity to the artery walls.

The fact remains that most of us will have high blood pressure. Hopefully, it won't occur until late in life, but for many it is a reality as early as our 30s or 40s. Denying it doesn't do much good. In fact, high blood pressure is one of the most controllable factors in health, with or without medication.

With all that said, what is a normal blood pressure? That may be among the most contentious of questions. Next blog post: What if "normal" blood pressure is really high blood pressure?