The Health Curve

High Blood Pressure: The Silent Killer - with Dr. Jaspal Gill, Cardiologist and Clinical Research Fellow at the University of London

• Dr. Jason Arora • Season 1 • Episode 12

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High blood pressure affects nearly half of all U.S. adults, yet most people don’t know they have it. In this short episode, we unpack what blood pressure really is, what causes it to rise, and why it's often called the "silent killer." 

Host Dr. Jason Arora and cardiologist Dr. Jaspal Gill walk us through what’s happening inside the body, how to measure it properly, and how to catch the early signs before it leads to something more dangerous. 

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In this special 4-part series on heart diseases, we're going to give you something that's getting harder and harder to come by: time with a cardiologist. 

Access to medical care is a growing challenge—especially when it comes to specialists. In the U.S. today, a single cardiologist may be responsible for thousands of patients, and nearly half of all U.S. counties don’t even have one. 

We’re joined by Dr. Jaspal Gill, Cardiologist and Clinical Research Fellow at the University of London, to break down the fundamentals of the most common—and most critical—heart conditions: high blood pressure, heart attacks, stroke, and arrhythmia.

SPEAKER_01:

Hello and welcome to The Health Curve. I'm your host, Jason Arora. In this special four-part series on cardiovascular health, we're going to give you something that's getting harder and harder to come by. Time with a cardiologist. Access to medical care is a growing challenge, especially when it comes to specialists. In the United States today, a single cardiologist may be responsible for thousands of patients. Nearly half of all US counties don't have a single practicing cardiologist. And within just five years, we could be facing a shortage of up to 15,000 cardiologists across the country. So whether you're managing your own heart health, helping someone you love, or just want to understand your body better, this series is for you. Over the next four episodes, we'll be breaking down the fundamentals of the most common and most critical heart-related conditions. High blood pressure, heart attacks, stroke, and rhythm disturbances, also known as arrhythmias. We're very lucky to be joined by Dr. Jaspal Gill, a cardiologist and clinical research fellow at the University of London in the UK. Dr. Jaspal Gill will walk us through the basics of each condition, what it is, what's happening inside the body, how to spot the warning signs, how it's treated, and the key things you need to know to stay informed and prepared. This episode is on high blood pressure or hypertension, High blood pressure is one of the leading causes of premature death worldwide. It directly puts you at risk of heart attacks, stroke and other serious medical conditions. And around half of U.S. adults have high blood pressure. Nearly 1.5 billion people worldwide are estimated to have it. And it is massively underdiagnosed, meaning more people likely have it than we think. Jaspal, thank you so much for joining us. I'm glad to be here. So let's start with high blood pressure. Can you tell us a little bit about what it is, what's happening in the body, and how we treat it?

SPEAKER_00:

Yeah, so high blood pressure is a bit of a silent killer, really, because most people don't have any symptoms relating to it. So people don't think it really matters at all, but it's really, really important. And what's happening in your body is your blood is going around all the time. It's going around being pumped from the heart, going into vessels which are arteries, moving into all your organ tissues, and then coming back to the heart in vessels that are called veins. Now, high blood pressure is referring to the pressure of the blood that's in the arteries, so when it's being pumped out of the heart, and it's in those main blood vessels there. And your blood pressure goes high for a few different reasons, many of which are related to the process of aging, but there are a few different things that can accelerate it. And what happens is that you have stiffening of your blood vessels. And in addition to the stiffening of those blood vessels, you get what we call an atherosclerotic deposit, which is just a fancy way for saying that there's fat building up within the walls of the blood vessel. And the combination of these two processes means that those blood vessels are less able to accommodate the changes in blood pressure that we have. That is normal with heart disease. pumping and that we see in our normal day-to-day life. And with that reduced flexibility and that reduced size of the blood vessel, because there's fat now in it and it's obstructing it, that results in an increased blood pressure, which is what we're measuring when you wear a cuff around the arm, we're measuring that blood pressure.

SPEAKER_01:

So the arteries become very stiff over time and Basically, it just makes it very hard for the body to increase blood flow, right? Because these arteries are very stiff, these blood vessels are very stiff, and they're also a bit blocked. Firstly, what causes that? What makes them stiff and what causes them to block?

SPEAKER_00:

So there are a few different things that we can't change. But fortunately, there are a few things that we can change. As we get older, our blood vessels are more likely to get stiffer. there's also a higher likelihood of having these fatty deposits within the blood vessels. In addition to other things, so for example, if we smoke, that can increase both of those quite significantly in addition to alcohol intake. Other things that we need to take into consideration are our diet. If you're eating more fat, you're having more cholesterol, there's a higher likelihood that your body's going to deposit that not only in just fat that you can see, but also within the blood vessels which you can't see. We can detect it with medical tests, but it's not something that's readily visible to someone who isn't a physician. And in addition to that, exercise. The more exercise we do, we're countering the effects of having fat and we can actually try and reverse and reduce the amount of fat that is in our blood vessels and try and recreate that flexibility and that sponginess that the blood vessels used to have. So these are all the things that play into what our blood vessels are like. In addition to other medical conditions, And what we're discussing is something called primary hypertension. So hypertension without a medical cause. Because there are other causes for having high blood pressure. For example, people have hormonal problems. Some of the hormones can really increase your blood pressure. But that's not usually what we refer to when we say this person has hypertension or this patient has high blood pressure. We would call that a secondary cause of hypertension. of high blood pressure because it's got another cause. And actually treating the high blood pressure is not the main issue there. You need to treat the underlying cause. So this is where we call primary hypertension, which is where it has this multifactorial causes to it.

SPEAKER_01:

Right. So over time and due to different lifestyle factors, which we've discussed a lot on this podcast already, there are things that can make the blood vessels more stiff and can cause partial blockage of the blood vessels. So why is it a problem that the blood pressure is high?

SPEAKER_00:

So this almost becomes a self-perpetuating problem with high blood pressure. And the reason for that is because when your blood pressure increases, your blood vessels don't like it. And how they adapt to it is by becoming more stiff. And so it becomes a vicious cycle. And so it tends to get worse and worse and worse. And the overall problem for that is that it can affect the different tissues and different organs that are within the body. starting from where the blood's being pumped from, from the heart. If the heart has to pump to create these higher blood pressures, then it's having to work harder. And that means that it's more difficult for it to pump the blood around. And in some cases, people's hearts can adapt to that. They can become thicker and they can become what we call hypertrophy, which means they just become big and thick. And that can affect how the heart is pumping itself. So that's something that we want to try and avoid. And the way that we try and avoid that is by trying controlling the blood pressure. In addition to what's going on in the actual heart, what happens in these little blood vessels is that when they become stiff and they've got these atherosclerotic plaques in them, they're fatty, there's a higher risk that they can either burst themselves. So you've got a higher risk of bleeding and that can happen in things like a stroke. Or there's a higher risk that that little fatty bit within the blood vessel, that can actually have a little rupture as well. And when that ruptures, the blood clots there. And so from what happens to, from when you've got a blood vessel, which is open, but there's a little bit of fat that's kind of blocking it a little bit, but there's still blood flowing. What will happen is if that ruptures and there's a clot that forms, that clot will completely obstruct the blood flow. And that means that that bit of tissue or that organ that's downstream of that doesn't get the blood that it needs. And of course, if tissue doesn't get blood, it dies. And so, for example, that's also one of the ways that we can have strokes. In addition to that, that's what happens when we have a heart attack, when we have a myocardial infarction. That's the mechanism that we're seeing. So by controlling our blood pressure, we reduce the likelihood of one of these outcomes from happening, and also it helps our overall heart health.

SPEAKER_01:

So this process is occurring in the blood vessels over time, and it can cause other diseases afterwards. Yeah, certainly.

SPEAKER_00:

In terms of the large blood vessels, those are the main things that I've just kind of spoken about. So it can increase the rates of the actual blood vessels failing themselves. So that can either cause bleeding or things called aneurysms, which is when there's kind of an outpouching from that blood vessel, which have a higher likelihood of rupture and bleeding compared to a healthy blood vessel. It can cause blockages within the blood vessels and different tissues that can cause either heart attacks or strokes. If it affects, for example, a blood vessel that's in your arm or in your leg, it can cause your leg or your limb to not get the blood flow that it needs. And actually that can mean that people can lose their limbs from this. And that is something that we certainly see, especially in people who have multiple problems with their blood vessels, often high blood pressure, hypertension. We're seeing coupled with people who are either smoking heavily or who have badly controlled diabetes. That as a combination is particularly puts people at risk of these things. These are the main big blood vessels that we're seeing. And by that, I mean blood vessels that we can see. They're still pretty small. Some of these blood vessels are only a couple of millimeters across, but we can still see them with our eyes. But there's a whole process that's happening microscopically with blood vessels that are too small for us to see. And that's where it's affecting things like, for example, our nerves. It's affecting our kidneys. And actually, there's more and more evidence amounting that this is actually a contributing factor towards what's happening in dementia. and these kind of disease problems. So there's a lot more for us to still find out about having high blood pressure. But what's very clear is that if we want to try and reduce our risk of having one of these problems, we need to try and get it under control.

SPEAKER_01:

Right. So how do we test blood pressure? How do we know that it's high? And how do we diagnose high blood pressure?

SPEAKER_00:

So the most common way that we check blood pressure is with a blood pressure cuff. So that's a cuff that usually goes around the top of the arm. And we're inflating that cuff to basically equalize the blood pressure that's in the blood vessels within our arm. And that's how we're measuring what the blood pressure is. Now, there's a big caveat to that. And that's that there's a lot of people who have what we call white coat hypertension. And that means that when they're in a medical setting, because of the stress that goes with that, some people get quite worried about what their blood pressure reading is. And then obviously that's a vicious cycle because then you get a bit stressed and then that shoots your blood pressure up. And so then your reading goes up. And then if you see the numbers in front of you, your blood pressure goes up more because you're like, oh my gosh, why is it going so high? And we call that white coat hypertension. And so often in people who we suspect that this is the case, we often do what we call ambulatory blood pressure monitoring. And that's just wearing that blood pressure cuff, but wearing it for 24 hours or so, letting it take readings at different time periods throughout the day so that we get a better feel of what your blood pressure is like. in your normal comfortable setting rather than in the kind of slightly more stressful setting, be it in hospital or in a clinic.

SPEAKER_01:

And people can also get their own coughs online like at Amazon, etc. Are they any good and can people check their own blood pressure?

SPEAKER_00:

Yeah, definitely. Usually medical ones are calibrated. So it's important to make sure that that initial calibration has occurred, which is actually a little bit difficult to do by oneself. But if you're in contact with your family medicine practitioner or your general practitioner, they can often help you with calibrating it. They often give you information about, for example, what your pulse rate is as well. So it's very important to make sure you're reading the right number. Blood pressure is given in two numbers, a higher number and a lower number. And that's reflecting the blood pressure when your heart is pumping. So when the heart's pumped as hard as it can, and also when the heart's relaxed. That's why we get the two different blood pressure readings that you'll see on the blood pressure card.

SPEAKER_01:

We'll get back to this conversation in just a moment. But if you're finding this episode helpful, here's a quick ask. Take a second to follow or subscribe to the Health Curve podcast wherever you're listening. And if someone in your life would benefit from this episode or any of the others you've heard, please send it their way. All right, let's get back to it. Can you briefly tell us what it means if the big number is higher or or if the small number is higher, what do each of those represent in terms of high blood pressure?

SPEAKER_00:

So the bigger number is representing when your heart's squeezing, basically, and the lower number is when the heart is relaxed. And essentially, having too high either of these can be a problem. If the higher number is too high, then that means your tissues are being exposed to that very high blood pressure, even if it's only for a shorter period of time. But even if the lower number, which is the diastolic number, pressure is high, that means your tissues are being exposed to a high blood pressure still. So both of them are equally important when we're assessing what the effects of blood pressure are. Now, what we've mentioned earlier is that most people don't have symptoms related to blood pressure. And that's the vast majority of people, 99.9% of people. But there are some very small circumstances where you can actually have some symptoms related to it. And that's usually when your blood pressure is very, very high. And it's usually referring to that higher number that we're talking about, where people can start having symptoms related to the blood pressure. And often it's things like visual symptoms, perhaps feeling a little bit dizzy and things like that that are related to it.

SPEAKER_01:

How is high blood pressure treated? So

SPEAKER_00:

the first thing that you'll be asked to do, if your doctor thinks that you've got high blood pressure, is that you've got the opportunity to try and control that with lifestyle. Reducing your salt intake, Salt draws fluid into the blood vessels and that makes your blood pressure go higher. So we want to try and reduce the salt that we eat. Reduce your weight if you're obese or overweight. Reducing the weight is really, really important. Increasing the amount you exercise and changing your diet. Diet to reflect more healthy fruits, vegetables, less processed food that incorporates the reduction in salt that we spoke about as well. So that's going to be the first thing that you have to do. After that, it's going to be medications. And I should say that medications are the easy way out. Most people should be able to control their blood pressure just by controlling their lifestyle. It's just a question of how that fits into the rest of their health and lifestyle and well-being. But medications definitely do have a role. And the main medications that we use, they all work in similar ways, but they mainly work to try and relax those blood vessels and try and change some of the hormones within our body that can increase your blood pressure. Because we do need blood pressure within our body. Too low blood pressure for us is not good either. Your body does need to maintain a blood pressure, so there are hormones that are there to do that. But that's great because it means we can exploit those when we're using medication.

SPEAKER_01:

How often is high blood pressure the cause of heart disease? Is it present in all or most cases?

SPEAKER_00:

I can't say all cases, but I think definitely in most cases of people who have heart disease, or who have cardiovascular disease, which is including things like strokes or problems in the blood vessels and the limbs, a good proportion of those people will have high blood pressure. And the main thing is that people with high blood pressure don't have symptoms related to it. So it's only really detected if, for example, you have something related to the cardiovascular system and then it prompts doctors to check it, or if they're just opportunistically checking it themselves, or if you yourself are motivated to go and get a blood pressure cuff and check it yourself as well. So a lot of people might find out that they've got a new diagnosis of high blood pressure at the same time that they've had a stroke or something like that. But actually they would have had high blood pressure probably years and years. It's just that it's manifest now because one of the complications of it has arisen.

SPEAKER_01:

And from what age do you think people should start getting their blood pressure checked?

SPEAKER_00:

So I think usually we'd say from probably about the age of about 40. In the UK, where I'm practicing, we usually have our well-man checks around that point and well-woman checks from the age of 40 to 45, where we can invite patients in to be screened for simple things like high blood pressure, checking heart rhythms, checking things like diabetes, and so on and so forth.

SPEAKER_01:

And so the takeaway for our listeners is that you have a silent condition here in high blood pressure that is present before a lot of people who have heart disease. actually find out that they have heart disease. And so there was a big opportunity to address heart disease upstream by looking into your blood pressure. And you can check it very easily. You can get a cuff online and that will still help you measure your blood pressure or at least directionally understand if it's going up or not. And if you have the opportunity to talk to your general practitioner about it, then you will be able to do that. If you can't get an appointment, this is probably the next best thing. And most of the issues with high blood pressure can be addressed with lifestyle changes, which we've talked about a lot on the podcast. So high blood pressure is not something to be ignored. What are some of the common misconceptions and misunderstandings and myths about high blood pressure?

SPEAKER_00:

The one that I've most commonly encountered is that people either completely blame their high blood pressure on stress or they blame their stress on high blood pressure. Now, stress is mediated by a hormone called cortisol, which is the stress hormone. And part of what that does is it does increase blood pressure. The actual numbers of times when that is the actual cause for someone's high blood pressure is very, very, very, very low. Chronic stress for people can increase your blood pressure. It might be playing into it, but it's unlikely to be the sole cause of your high blood pressure. Blood pressure is a multifactorial thing. So you have to be able to address everything to try and help it. And if chronic stress is there for you, then yeah, definitely trying to address that will help, but it's not going to be the complete answer. It's not going to be the panacea for you.

SPEAKER_01:

And a few more that we've heard. So one is that people say that high blood pressure is just something that runs in their family, and so there's nothing they can do about it.

SPEAKER_00:

So there's definitely a genetic component to it. There are people who They've got a family history of having high blood pressure, especially at kind of younger ages. And those people, you might see them age 30 or sometimes in their 20s with high blood pressure. That kind of high blood pressure is more prevalent in the Afro-Caribbean populations as well in the African-American population. That's not a free pass to not do anything about it. That's an excuse. You've still got to control it. Most of the complications from having high blood pressure arise after having it for 5, 10, 15 years. So if that five years or 10 years is starting when you're 25, you might start getting complications at it. We're talking about heart attacks, strokes and things like that when you're 35. Whereas if you're having it, you're getting diagnosed with this when you're 60 or 70, then we're only talking about when you're in your 70s or 80s, where you might actually have a problem relating to it. So all of these things do really matter. They're important and controlling it is the most important thing.

SPEAKER_01:

A couple more. One is that People think that the type of salt they use makes a difference. They may say they use kosher salt or they don't use table salt on top of what's already been cooked in their food. Just try and unpack that a little bit more for us.

SPEAKER_00:

So I don't think the type of salt really makes a difference. The one that I've heard is that Himalayan pink salt is better for you than anything else. I don't think that really makes a difference at all. I don't think we've got any evidence to say that it makes any difference at all. One thing that I will say about salt is that people think that it means the salt that you put on your food, exactly as you said, table salt. It's what you've got sitting on your dining table. But actually, the real things that have got salt is processed food. For example, if you buy a loaf of bread from your supermarket that's got about 0.7 grams of salt per slice, the maximum recommended amount of salt, at least in the UK, is six grams for an adult. So you have two sandwiches, which are two slices of bread each, you're looking at two and a half grams of salt just in that. That's not without having putting some cheese or some ham in, which both as well have a lot of salt in them. Actually, the focus in on the salt in the diet, you actually really need to look at processed food because that's where the salt is hiding. It's very, very rarely going to be in the salt that you actually put on yourself. It's processed food, it's takeout food, it's chips, that kind of stuff, fries, all this kind of stuff has got a lot of salt in them.

SPEAKER_01:

What about alcohol? Is any amount of alcohol okay for your blood pressure?

SPEAKER_00:

So there was the traditional thinking that if you kept alcohol within the recommended limit, which is 14 units for women and 21 units for men, then your risk of developing problems related to it, for example, high blood pressure, is negligibly increased. And actually, I think data has arisen more recently that suggests that actually people who are teetotal do better. So no alcohol is the best. The less that you can drink and get away with is better.

SPEAKER_01:

Jaspal, thank you so much for joining us and walking us through that. Everyone, please join us for our next episode with Dr. Jaspal Gill, where we'll be talking about heart attacks.

UNKNOWN:

Thank you.