Healthy Blood Pressure

High Blood Pressure is a big risk factor for cardiovascular disease. High blood pressure not only leads to coronary vessel damage but it affects all small blood vessels (microvascular) and capillaries. Hence, high blood pressure is a risk factor for strokes, heart attacks, kidney failure, etc.. The reason why blood pressure damages small blood vessels is twofold. First, Bernoulli’s principle states that as the diameter of a vessel decreases the velocity of the liquid within the vessel increases. This increase in velocity causes more damage to the lining of the blood vessel because of the second reason; Second, end organs tend to have capillaries that branch off at 90 degree angles which leaves the vessels walls open to repeated damage and thickening. Over time, the repeated damage and thickening leads to plaque formation and decreased blood flow to the organ and subsequently higher blood pressure. If that plaque happens to break away it will completely block the blood vessel and cause an infarct (stroke, heart attack, etc).

So what is a healthy blood pressure? The committee that reviews the various studies on blood pressure and makes the recommendations for physicians to use is known as the JNC (Joint National Committee on the Evaluation and Treatment of Blood Pressure). Their last report (7^th) came out in December 2003. The 8^th report is due out in March of this year. For the average adult the recommended blood pressure is under 140/90. If you have heart disease or diabetes it is recommended to keep blood pressure below 130/80. In fact, the lower the blood pressure, the better as long as it is not too low. It is best to check your blood pressure throughout your normal daily activities and not just at the doctor’s office because the anxiety of the doctor’s office can raise your blood pressure. Caffeine can raise your blood pressure for up to 2 hours while smoking can raise your blood pressure for up to 30 minutes.

How do you lower your blood pressure? Smoking, Caffeine, and stress can all raise blood pressure but not long term unless you are smoking and drinking all day long which some people do. Salt (Sodium) is the big problem most people face with our western diet. Sodium is everywhere! Sodium makes you retain fluid and hence raise your blood pressure. This can be so drastic that if a person with heart failure has a large sodium rich meal (cured ham, brined turkey, Chinese food, Brats with Saurkraut etc) they can put themselves into fluid overload and respiratory failure from fluid filling up in their lungs.

If you have high blood pressure; you can lower your risk for stroke by 20% and heart attack by up to 50% by decreasing your pressure by 10 millimeters of mercury (e.g. 140/90 systolic to 130/80 systolic). The DASH diet is a low sodium diet that you can follow. Exercise temporarily raises blood pressure but long term lowers blood pressure. Relaxation lowers blood pressure as well. If you can’t lower your blood pressure with the above measures, medications may be necessary.

I am more than happy to answer any specific questions you may have on medications. In general thiazides and calcium channel blockers are considered first line agents. However, there may be a compelling indication for another medication. Every medication has its pros and cons, side effects, contraindications, etc. Genetics and race may even play a role in how well your respond to a specific medication. It is best to discuss with your physician which medication is best and most affordable. Fortunately, almost every class of blood pressure medication can be found on the $4 dollar formulary at your local pharmacy.