Ever wonder why you have a pulse? Obviously your pulse is there because your heart is pumping, but why can you feel it? Why does the blood vessel push against your fingers for a moment and then disappear under your skin?

The simple answer is that your blood vessels are flexible, not stiff. As the blood from the heart pumps through, the blood vessel can expand like a balloon and then shrink back as the blood passes. Unlike a balloon, the blood vessel doesn’t get stretched out with each expansion because the walls of the vessel are mostly made of smooth muscles that contract or squeeze back into shape again. The expand and contract pattern with each pump of the heart keeps the blood under pressure so that it flows in one direction. It’s like a water slide adjusting to each rider as she passes.

These smooth muscles move involuntarily (i.e. you can’t control them like an arm or a finger) to regulate the volume of blood in the vessel and how forcefully that blood flows. Blood vessels are not passive garden hoses but more like millions of tiny fans keeping the wave going in a tubular stadium. This is mind blowingly cool, but what does it have to do with hypertension and heart health?

When the smooth muscles in the blood vessel walls contract too much, they become stiff and tense or, if you will, “hyper tense” which causes the blood pressure to rise. Hypertension is another name for high blood pressure and contributes in a big way to heart disease. Statistics say that if 10 people have untreated hypertension, 5 of them will die of a heart attack and 3 of them will die of a stroke. Hypertension is dangerous if left untreated, but why?

Hypertension is a warning sign that blood is not flowing well in the body. Blood pressure goes up because the blood has to press harder to get through the vessels, i.e. the heart pumps extra hard. In our shipping analogy, hypertension is all of the sailors working harder and harder to get the ships to the docks, but not getting there any faster than they used to. After years of hard sailing, shipments are delayed or detoured and the sailors simply can’t sail up every tiny tributary like they used to because the way is clogged with pollution or traffic. Any body part of the world that receives fewer shipments than necessary will suffer. Another way to say it is that if a body part lacks blood, it also lacks oxygen which it needs for energy producing reactions within the cells, so it will not have energy and cells will die. If enough cells die, we develop symptoms.

Let’s take a trip around the body globe. Yes, I know the analogy is wearing thin, but I’m up a creek and dropped my paddle, so you’ll just have to drift downstream with me.

North America is the heart because “home is where the heart is” and my home is in North America. (Feel free to print out the map and draw your heart wherever you want.) If blood shipments to North America stop completely, the Earth dies; this is a heart attack. If the shipments slow down enough to almost stop, North America riots which causes pain; this is a heart attack that doesn’t kill you but gives you a chance to change. About half of people with untreated hypertension end up with a heart attack.

Asia is known for electronics manufacturing, so it represents our brain. The brain has been compared to a computer and we think about (or maybe with) our electronics a scary lot of the time. If shipping to Asia brain is cut off, we have a stroke. Maybe we die and maybe we just have some brain damage, but either way we suffer without our electronics. Poor blood flow in the brain can even cause vascular dementia. About one third of people with untreated hypertension end up having a stroke.

Africa is home to the Sahara Desert which has the most uninterrupted view in the world (I’m guessing) from the top of a dune on a cloudless day. Africa represents our eyes and hypertension is a sand storm. Eyes need nourishing blood to see properly and when they don’t get enough, vision can become blurry or be lost completely.

South America is home to the Amazon River which processes a LOT of water so South America represents our kidneys which process and clean our blood. If the blood vessels inside of or leading to the kidneys are damaged, the blood can’t get in and flow through to be cleaned. The Amazon River becomes polluted and we need dialysis or die. The number one cause of kidney failure is high blood pressure.

Europe is the bones of the world because they have the most stone castles which are kind of like skeletons because they provided structure and protection in feudal society…stone and bone rhyme, shall we just go with that? Hypertension can lead to bone loss and osteoporosis because calcium is recruited from the bones to patch up tiny tears in the blood vessel lining.

Sorry, Australia, I’m out of body parts! I’m sure hypertension would ruin you too, though.

Hypertension normally takes many years to cause damage and not everyone will suffer the same symptoms or any symptoms at all. But I now understand why blood pressure is considered important enough to be checked regularly as a “vital sign”. Next week we’ll look at what we can do to help reduce hypertension.

A good man brings good things out of the good stored up in his heart, and an evil man brings evil things out of the evil stored up in his heart. For the mouth speaks what the heart is full of. Luke 6:45

Tune in next time for With All My Heart: Hypertension and Heart Health (Part 2)