The Silent Assassin

Like an unaware target of a vigilant sniper, most people with high blood pressure live their lives with no suspicion that danger lurks at all times.  Hypertension rarely causes immediate effects on health but its constant influence causes stress on blood vessels and the walls of the heart.  This leads to thickening of the artery walls causing them to become hard and more brittle.  The most dreaded complication due to this process is in the brain in the form of a stoke.  There are usually no warning signs of a stroke.  When blood supply to the brain is cut off it happens quickly and suddenly.  Depending on which portion of the brain is affected, the effects can be devastating.

The muscular walls of the heart respond to the stress of high blood pressure the same way a weight lifters muscles respond to working out, by getting bigger and thicker.  At first thought you may ask, "What is wrong with having a "buff" heart.  Strong, thick muscles are good for quick bursts of action but it is the lean, thin muscles of the marathoner that we would rather pattern our heart muscle after, not the hulk of a weight lifter.  Ideally we want that heart muscle to pump slow, steady and efficiently, beat after beat after beat.   When the heart muscle gets too big, it gets stiff and has a hard time relaxing.  The stiff walls of the heart inhibit the flow of blood into the chamber.  If less blood enters the pumping chamber, less blood is ejected.  To compensate for this, the heart speeds up, making it even harder to fill the chamber.  As it gets harder and harder to fill the pump, the blood flow to the heart backs up like a partially clogged sink and fluid starts to fill the lungs leading to a form of congestive heart failure.  This form of heart failure is completely preventable by controlling blood pressure. 

In addition to causing heart failure and strokes, high blood pressure can trigger a heart attack.  If the lining over a cholesterol deposit breaks open, the body will respond by creating a clot on top of that plaque (see below).  This can take a non important 50% blockage and turn it into a deadly 100% blockage resulting in damage to the heart muscle.  High blood pressure makes the likelihood of that lining being broken open much higher.  The higher the sheer forces on the blockage, the greater the chance of rupture.  

Other areas of the body can also be damaged severely by high blood pressure, including the delicate tissues of the eye and the specialized filters of the kidney.  When combined with diabetes, blood vessel damage is exceedingly more likely.  The vast majority of patients on hemodialysis (artificial kidney machine) have one or both of these conditions.

Waiting to lower blood pressure until something bad happens is a recipe for disaster.  First, make sure you know what your blood pressure is.  If you haven't been in to see your doctor, do so.  Put your arm in the machine at the grocery store or pharmacy.  If you have a family member with a home machine, try it out. There are two numbers associated with your blood pressure.  The top number (systolic pressure) is the pressure in your blood vessels as the heart contracts.  The bottom number (diastolic pressure) is the pressure after it relaxes.  Both numbers are important.  If either one of them are elevated, your blood pressure is elevated.  Normal blood pressure is to have your systolic less than 130 mm Hg and the diastolic less than 80 mm Hg.  Real damage start to occur when your levels are consistently greater than 140/90.  Next week I'll discuss what to do if your levels are too high.