Usually, I break the week’s topic down into something like the following: types, risk factors, symptoms, causes, treatment. Because heart disease is the number one killer of Americans, I am going to assume that most of that would be redundant for you and focus, instead, on the how and the why. I have a mental block for anything that I don’t thoroughly comprehend. For instance, I sometimes hear babies crying in the middle of the night and wonder where that strange noise is coming from. No matter how many times I have played craps, as soon as someone yells, “Yo Eleven!” or “Hard Eight!”, I get confused and lose all interest in playing. Perhaps, like me, you have a hard time wrapping your head around things you don’t understand. Having a better grasp of what blood pressure really is may inspire you to maintain it at a healthy level.
1. Blood pressure is the term that describes the force that the circulating blood puts on the wall of the arteries while passing through. The top number, the systolic pressure, is the maximum pressure that is exerted from the contraction of the heart, forcing the blood through your arterial system. The diastolic pressure is the minimum force that is still present during the relaxation between heart contractions or beats.
2. Who cares? Blood pressure is a reflection of how hard your heart has to work in order to get oxygenated blood to all the cells in your body. The higher your blood pressure, the harder your amazing heart is working. The harder it has to work, the greater your chance for heart disease.
3. Blood pressure is the result of three variables: heart rate, stroke volume, and the resistance in your circulatory system.
– Heart Rate – Generally, your blood pressure increases if your heart rate goes up in response to stress, temperature or hormonal changes. Therefore, anxiety, frustration, road rage and anything else that causes your heart rate to increase is bad for your heart.
– Stroke volume, the amount of blood pumped with each heartbeat, is a function of how hard your heart is pumping. It is usually fairly stable from beat to beat, but anything that increases your stress hormones will cause your heart to beat harder. Anything that causes you to retain water, like pregnancy, salt or dirty martinis, increases the volume of blood that the heart has to move, thereby increasing its workload.
– Resistance – Think of water flowing through a tube. The thinner the tube, the more force it will take to push the water through. Anything that causes thinning of the passageway through the arteries makes it more difficult for the blood to flow. Furthermore, anything that causes stiffening of the arteries makes them less flexible, therefore making it harder for the blood to flow through. Your heart will have to work harder if there is greater resistance in the arteries.
You may be thinking, “How is exercise a good thing when it increases my heart rate and increases my body’s demand for oxygenated blood?” Nice try. There is built in protection when it comes to exercise. When you work out, the arteries open up to allow more blood to flow through. The muscles that you are using tell the circulatory system that they need more oxygen and as a result, the resistance in the arteries decreases. This allows you to maintain a relatively stable blood pressure while you are exercising. As a person who hates to sweat, I wish this wasn’t true, but it is – sorry. So, after a long car ride with toddlers, you may be sweating, your heart may be racing and you may feel that you just ran a marathon. Unfortunately, unless you were running alongside the car making faces at them through the window, you hurt your heart. The stress of trying to find the lost sippy cup did increase your heart rate, but without the feedback from exercising muscles, it also increased your blood pressure. You were correct — okay, okay, it was me — I was correct in telling them that they are going to give me a heart attack. Whose bright idea was it to make it illegal to drink in the passenger seat of the car?
4. High blood pressure is defined as anything over 140 systolic or 90 diastolic. Based on the explanations above, in order to make your heart work as easily as possible, you are shooting for a blood pressure of 120/80 or less. If you don’t know what your blood pressure is, go find out. Even if you hate the doctor, there are screenings everywhere, and they usually offer free coffee.
5. Low blood pressure – one of my teachers once told me that blood pressure is a necessary evil — the lower the better. He meant the lower the better as long as you are asymptomatic and functioning. Symptoms of low blood pressure including fatigue, lightheadedness and/or dizziness need to be evaluated for an underlying medical condition. If your blood pressure is 90/60 and you feel great, good for you.
I could do a month on blood pressure, as there is so much to say about it, but you would fall asleep. Hopefully, you get the idea that low blood pressure is good, because your heart does not have to work as hard. Exercise is good because it strengthens your heart muscle. In the same way that having strong muscles will make it easier and safer for you to lift heavy loads, having a strong heart will make it easier and less taxing to pump the blood through your body. As there is no warranty, extended or otherwise, on this organ, you may want to promote its longevity. A healthy blood pressure is a great start. Tomorrow, Atherosclerosis and Cholesterol 101.