HIGH BLOOD PRESSURE Author: Joan MacDonald, RN, BScN, M.Ed., National Clinical Consultant, VON Canada About one in six adults have hypertension. I am often asked about high blood pressure and what do "the numbers mean?" Your body has a given amount of blood, which flows to the remotest tissues giving oxygen and nutrients. The relationship of the pressure of this fluid against the size and tension of the blood vessels holding your blood is what your blood pressure is. There can be many reasons why blood pressure is high or low. Imagine if your blood vessels were a container like a balloon, which could hold a cup of water. If the container became smaller and narrower, the pressure against the walls of the container would become higher. The inside diameter of our blood vessels narrow as we age with fatty plaques, and the blood vessel itself becomes less elastic and harder as we age. So diet and ageing itself plays a role. The pressure would also be higher if you tried to overfill that confined space. Many natural chemicals and hormones in our body regulate our blood volume, as do our kidneys and the efficiency of our heart as a pump. This affects our blood pressure too. When your Doctor treats hypertension, the goal then is to reduce pressure against the arteries sometimes by reducing the pressure of the volume of the fluid; and to try to slow down atherosclerosis (the forming of fatty substances inside the artery wall that can narrow the vessel) sometimes by combinations of medication and diet. One high blood pressure reading by itself usually doesn't label you as hypertensive. There will be an average of readings before your doctor attaches significance to one number. The systolic pressure, (the top number of a blood pressure reading) is the maximum pressure against the arteries by your heart's left ventricle when it pumps. The diastolic pressure (the bottom number) is the constant source of pressure that is always against the arterial walls all the time just because there is a certain volume of blood in the arterial walls all the time. Another important number is the "pulse pressure", which is the difference between the two numbers and it shouldn't be less than 20 or more than 50 mm Hg. This last number gives your doctor an idea of the heart's stroke volume. A normal BP in a young adult is 120/80 mm Hg. High blood pressure is a persistent elevation above 140/90; and low blood pressure is often given as below 95/60. A reading is best taken with the right size of blood pressure cuff, resting for 5 to 10 minutes before, and at least 30 minutes after eating or exercising (as both can raise pressure a bit). There are about seven different types of medications that can help lower blood pressure. As follows: 1) Diuretics (Hydrochlorothiazide, Furosemide), gets rid of extra water fluid from your body; 2) Alpha1-receptor blockers (Terazosin, Doxazosin), 3) Direct vasodilators (Hydralazine), 4) Central Alpha2 - agonists (Clonidine) all open your blood vessels wider; 5) ACE inhibiters (Enalapril, Lisinopril), opens up your blood vessels too

and helps your kidneys work better; 6) Calcium channel blockers (Amlodipine, Metoprolol) opens your blood vessels and keeps your heart from working too hard; and finally 7) Beta-blockers (Atenolol, Metoprolol tartrate) keeps your heart from working too hard and also protects blood vessels from damage. Your doctor has a lot of choices to work with, so if you have side-effects from one medication do speak up as something else possibly can be tried. You can do things too!

• You can try to reduce that fatty build up in your blood vessels by cutting your fat and cholesterol. Total fat should not be more than 25%-35% of your total calories each day.

• Decrease water retention in your blood vessels by avoiding a lot of salt. THIS DOES NOT MEAN DO NOT DRINK WATER or FLUIDS! You need a lot of fluid each day, but you also need to excrete a lot. Salt pulls more fluid specifically into your blood vessels. Please don't use more than a teaspoon of salt per day and look at food labels to avoid foods that contain more than 400mg of sodium-chloride (salt), deli-foods, luncheon meats, pickles, and canned soups & vegetables.

• Some diuretics make you lose potassium. Eating foods with potassium, calcium and magnesium can help, like bananas, oranges, milk and yogurt.

• If you are overweight, lose weight and get some exercise. Good luck, you may find you get excellent control!