Flyer Health: Blood Pressure

I want to tell you about a friend of mine. His name is Phil, and I’m worried about him. See, Phil is overweight, he smokes, he works a desk job, so he never gets much exercise, and he eats canned soup and pickles every day.

What’s even more worrisome is that his dad died of a stroke when he was only 50 years old. So why am I worried about my friend?

Well, I’ve never sat him down and taken his blood pressure, but I’d be willing to bet it’s pretty high. And if your lifestyle sounds anything like Phil’s, I’m worried about you too.

What is Blood Pressure?
Every time your heart beats, it sends blood out into your vessels. The heart is a strong muscle, and it is able to pump blood with a lot of force. The force of the blood on the walls of your vessels is called the systolic pressure—it’s the pressure that you feel pushing against your finger when you take your pulse. When the heart relaxes to take blood in, the arteries don’t just go slack—there is a resting force that remains on the arteries even in the absence of systolic pressure. This is called the diastolic pressure.

Blood pressure is read as two numbers. The convention is to put the systolic pressure over the diastolic pressure like a fraction. A normal blood pressure would read something like 115/75.

To visualize what is happening in your blood vessels while your heart is pumping blood, I think it’s useful to imagine a garden hose. Say you’re standing next to the faucet attached the hose, and you open it up half way. What happens in the hose? The hose will tense up as it fills with water, and it will be much harder to compress as long as there is water pressure inside the hose. If you close the faucet, then the hose will slacken and go back down to its normal shape and stiffness. This is similar to what happens in your vessels while your heart is pumping.

What is Hypertension?
Hypertension, or high blood pressure, is when the pressure in your vessels is greater than what is considered to be healthy. In the US a blood pressure below 120/80 is considered normal, and anything over 140/90 is considered hypertension. There is an intermediate range between those two values called prehypertension that indicates a heightened risk of developing hypertension in the future.
Hypertension itself is not an illness. Having a high blood pressure has no associated symptoms. It is estimated that millions of people in the US are hypertensive without even realizing it because they otherwise feel fine.

The list of complications related to hypertension is long, but some of the most common include: stroke, heart attack, and kidney damage. The reason for the associated complications is usually related to damage to blood vessels.

Returning to the garden hose analogy, let’s imagine that we open the faucet on the hose full blast—now the hose will stiffen up even more than before. In addition, if you leave the faucet open for a long time, you might notice a ballooning out of the hose due to the high water pressure inside.

The same thing happens in your vessels. If you have hypertension for many years, your blood vessels can become damaged and altered from the long-term effects of the high blood pressure. This can lead to aneurysms or breaking of vessels. Furthermore, the blood vessels don’t like to be under this much stress, and over time they can become stiff and rigid from the high pressure. This actually makes pumping blood harder for the heart, and over time the heart can actually change size and shape in unhealthy ways.

What are the Risk Factors for Hypertension?
If you remember my friend Phil from the beginning of the article, he actually displayed a lot of the classic risk factors for hypertension, and that’s why I’m so worried about him. The classic risk factors for hypertension include being overweight or obese, tobacco use, lack of physical activity, too much sodium and not enough potassium in the diet, and family history. Other risk factors include: old age, heavy alcohol use, and stress. Race is also a factor in hypertension; high blood pressure is more common in blacks than whites.

Additionally, it is now believed that a lack of Vitamin D may play a role in hypertension, but this issue is still being debated.

What can I do about my Blood Pressure?
It is estimated that 1/3 of Americans have hypertension, and of that 1/3, it is estimated that a further 1/3 of those people don’t even know it. If you haven’t had your blood pressure checked recently, take this as a sign that it’s time to have it checked. This is easier than it may seem. Most pharmacies have automated booths where you can have your blood pressure checked for free. If your blood pressure is over 140/90, it is recommended that you discuss treatment with your doctor. If your blood pressure is above 120/80, but below 140/90, you should consider lifestyle changes you can take to prevent developing hypertension in the future.

If your blood pressure is elevated, or if you’re concerned about developing hypertension in the future, here are some ways to achieve or maintain a healthy blood pressure. This is exactly what I plan on telling my friend Phil next time I see him.

  1. QUIT SMOKING – smoking can transiently raise your systolic blood pressure by 20mmHg. Smoking also increases risk factors for hypertension-related diseases such as stiffening of the arteries. Also keep in mind that smoking is related to several other diseases such as lung cancer and emphysema, so quitting smoking is one of the best all-around things you can do for your health.
  2. GET MORE EXERCISE – you don’t have to get nearly as much as you might think to have positive health benefits. Some studies say that 30 minutes of walking daily is enough to reduce your risk of hypertension.
  3. EAT LESS SODIUM – there is still some debate about how exactly a high sodium diet contributes to hypertension, because some people can eat a ton of sodium without any problem, whereas other people develop hypertension with relatively moderate sodium intake. There is little debate, however, about the fact that cutting your sodium intake to less than 1500mg per day can help lower your blood pressure. Lowering your salt intake can be very difficult, however, because many processed foods contain deceptively high amounts of sodium.
  4. EAT MORE POTASSIUM – this suggestion goes hand in hand with #3 above. To achieve maximum benefit from a low sodium diet, you need to also get lots of potassium. High potassium foods include fruits, vegetables, dairy, and fish.
  5. CHILL OUT! – don’t you love it when health advice tells you to just relax? Stress can contribute to a rise in blood pressure. Relaxation techniques such as yoga and meditation have been shown to help lower blood pressure.

Unfortunately, some people are just at a higher risk of hypertension because of things outside of their control such as race, age, and family history. These people would be well advised to follow the steps above, but also consult with a doctor. There are many effective medical treatments to control hypertension when diet and exercise are not enough.

Below are some useful links for people wanting to know more about hypertension.

[Photo by Scout Seventeen via Flickr and Creative Commons 2.0]