If you have a high blood pressure concern, or you are on treatment for hypertension, you may wish to watch this video. The transcripts are below, but let me also point you to this medical journal article, called On Redefining Hypertension. I wrote it with my colleague Dr. Herbert Fred and you may find it informative.
Today I’d like to talk about high blood pressure management, because I think this is one area where there is a lot of confusion, even among doctors. Just in the last couple of years, there have been studies and recommendations that conflict with each other about what constitutes high blood pressure, how to treat it, and so forth.
I will talk briefly about what high blood pressure is, why there is confusion about it, and what I think is the proper way to deal with people who have blood pressure concerns.
What is high blood pressure?
As you know, the blood, which is a fluid, circulates in the blood vessels, which are like tubes, under the action of the heart, which acts as a pump. Anytime a fluid moves, it exerts a certain pressure against the wall of the tubes, and because the action of the heart is pulsatile, it squeezes and relaxes, the blood pressure goes up and down with each heartbeat. That’s why there is a top number and a bottom number, say 130/80. The top is the blood pressure immediately after the heart squeezes, and the pressure is at its peak, and the bottom number is when the heart relaxes and the blood pressure drops before the next heartbeat.
Now if the blood pressure gets to be too high—and it doesn’t matter whether it’s the top number or the bottom number, then complications can occur. This is called hypertension, and if you have hypertension that is untreated for many years, you can go on to sustain damage to the heart, the kidneys, the blood vessels, and the brain. Hypertension is the most common contributor to heart failure, stroke, kidney failure and other complications that we absolutely want to avoid.
I will leave aside the question of what causes the blood pressure to be high. Perhaps we can discuss this in a separate episode, but the main point here is that if the BP is elevated, then it can create problems over time.
The problem comes when you try to decide how high is too high, and that’s where I think most of the confusion comes from. And the confusion, in my opinion, comes from the fact that people—and that includes doctor—focus too much on the number itself, or a particular number, like 140/90 to define high blood pressure.
There are many reasons why defining high blood pressure strictly on the basis of cut-off numbers is problematic. The first one is that the blood pressure varies all the time depending on what you are doing, what you’ve been eating or drinking, what the needs of your body are, whether you are nervous or not, etc. In fact if you chart someone’s blood pressure continually during a 24 hour period, the difference between the lowest value and the highest value during the day can be double.
So, depending on when the blood pressure is measured, you may get totally different numbers. And it is well known that people’s blood pressure is frequently higher when they are in the doctor’s office, and that’s called “white coat hypertension,” but for some people it’s the reverse: in the doctor’s office the blood pressure is lower than when they are at home. This is called “masked” hypertension. It is masked, because unless you measure the blood pressure at home, you don’t know that it is higher than in the doctor’s office.
There is another reason why focusing on cut-off numbers to define high blood pressure is a problem. That’s because any cut-off number you pick does not represent any meaningful threshold in the blood pressure. You see, it’s a continuum: the lower the blood pressure, the better. There is no abrupt dividing line that says “anything above this number will cause complications, and anything below this number will not.” There is a gradual increase in risk of complications, the higher you go.
The numbers that are commonly used like, say 140/90 are arbitrary and used for convenience. In fact, in some countries they may use other numbers to define hypertension, like 150 or some will say 135.
So how do get around this confusion?
Well, in my opinion, the key is to recognize that it is not the pressure itself that is the problem, but the effects that the pressure is having on the body. And what’s clear, is that different bodies will react differently to the same amount of pressure, so that a pressure of 150 may be tolerable for one person, but too high for another one.
And the way to determine that is to examine the heart, the blood vessels and the kidneys, and see if there are changes that indicate that the pressure is starting to have some effect on those organs. If it is, then we should take it seriously. If not, then the blood pressure may be fine where it is, and we don’t need to think about treatment, but can afford to monitor things instead of starting a medication.
Now in general I am neither for nor against watching things or starting drug therapy. What is important is to do the right thing as best as possible. You don’t want to start drugs prematurely, and on the other hand you don’t want to want to sit around and wait while the blood pressure is starting to take a toll.
So the idea of looking at the organs and see that they are being affected by high blood pressure is how you can avoid overtreating or undertreating. And we have many tests available that can help us make that determination. We can look precisely at the heart and measure the heart chambers and look for any early enlargement, we can look at the blood vessels and see that they remain healthy and flexible, we can monitor the kidneys, etc., and these tests are very helpful to help sort things out.
So in summary, high blood pressure is a very important condition that affects millions of people and has serious consequences. But defining high blood pressure on the basis on arbitrary cut-off numbers is not the best way to go. Instead, we should use the tools that are available to us to see if the organs like the heart, kidneys, and blood vessels are affected by the blood pressure, and tailor our treatment accordingly.
I hope you have found this episode useful. As always the show notes ill be on our website, along with other informative links. Until next time, thank you for your attention and be well.