PODCAST: What Is a Normal Blood Pressure? What's High? Can You Lower It?Nov. 15, 2022
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Nearly half of U.S. adults have high blood pressure, or hypertension, and only about 1 in 4 of those have the condition under control. What can you do to control the condition — or, better yet, prevent it from developing in the first place? In today's episode, we get the lowdown on high blood pressure, the leading cause of stroke and a major risk factor for other concerning health conditions.
Hosts: Zach Moore, Todd Ackerman (interviewer)
Expert: Dr. Kershaw Patel, Cardiologist
Notable topics covered:
- Why high blood pressure is known as the silent killer
- High blood pressure symptoms that suggest you may have it
- The health conditions that high blood pressure can cause
- The level at which blood pressure is too high — or too low
- Whether there's a need for continuous blood pressure monitoring
- The reliability of those blood pressure kiosk machines
- Ways to control high blood pressure without medication
- The latest on when's best to take blood pressure medication
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TODD: It's good to have you here today with us.
DR. PATEL: Thanks so much for having me and looking forward to this conversation — what I think is a very important topic. Part of the reason it's so important is because of how common it is, as well as how much of an effect it has on cardiovascular disease. So, we know about 100 million adults in the United States have hypertension, or high blood pressure, that's stably elevated. And high blood pressure is a major cause for heart disease, as well as strokes and kidney disease. It's one of the leading causes for kidney disease, which is an important complication. I think when we talk about high blood pressure, it's important that we realize it affects not just the heart, but also the brain, the kidneys and other organs in the body. With 100 million adults in the United States, there's a very high proportion of individuals who are at risk, then, for developing heart problems.
TODD: Are the numbers getting any better or people getting better at monitoring their blood pressure?
DR. PATEL: Nowadays, there are many types of ways we can monitor blood pressure, and I think it's being emphasized more and more — including in my own personal practice. So, we are catching high blood pressure more. What I mean by that is we are recommending that people monitor their blood pressure at home in addition to measuring it in clinic. And, so, the rates of high blood pressure, we may be diagnosing it more.
TODD: Okay. So, tell us a little bit about what exactly happens when your blood pressure is high.
DR. PATEL: Basically, when we talk about high blood pressure, it's the blood inside the vessels of the body that deliver a certain type of force on the walls of those blood vessels. And, so, when that force increases, that causes the pressures to go up. And when we talk about blood pressure, we commonly talk about two numbers, a top number and a bottom number. And, so, what those refer to is basically the force of the blood in the blood vessels. And when the heart is pumping, as well as when the heart is relaxed, [if that] force is high — and when we talk about high blood pressure, we're typically talking about anything more than 120 millimeters of mercury for that top number would be considered to be a little bit high. And then depending on how high that blood pressure is, is how we categorize if the blood pressure is elevated or hypertension. And then within those classifications of hypertension, is it stage one or stage two? Similarly, for the bottom number, there's a force delivered by that blood in the blood vessel. And that happens even when the heart's not beating. And that's how we get blood to the different organs in the body. And, so, when that number gets to be above 80 millimeters of mercury, we start to call that abnormally high. So that blood pressure range, we think, should be less than 120 for the top number and less than 80 for the bottom number. The top number is the systolic blood pressure, when the heart is pumping, and the bottom number is the diastolic blood pressure, and that's when the heart is relaxed. And, so, we know that the heart is constantly beating, sometimes ejecting blood around the body. The other time it's relaxing and before so it can eject more blood for the next heartbeat.
TODD: How about low blood pressure? Is that much of a problem?
DR. PATEL: Yeah. So, we sometimes see complications of low blood pressure. Those are symptoms that people have, like lightheadedness or dizziness. Those can be symptoms of low blood pressure. Typically, that's seen in individuals who may not be as well hydrated, potentially taking too many medications to lower their blood pressure, and so it's important that we monitor these things so that we avoid the low blood pressures. It's not necessarily that common. It can be more of a side effect, as opposed to somebody just having low blood pressure. Typically, if somebody has low blood pressure, that could be a sign that there's something potentially else going on, like potentially some actual heart disease or some other cause for the low blood pressure.
TODD: Talk a little bit more about the consequences of high blood pressure. I always think of it mostly as a risk for stroke, but that's not all.
DR. PATEL: Yeah, absolutely. So high blood pressure, you're right, is definitely a major risk factor for stroke. And probably the most beneficial effects of lowering blood pressure is actually reducing the risk of stroke. And that's important because a stroke can vary in how intense or severe that it is. It could really affect somebody's quality of life. So, stroke is a major complication of high blood pressure that's very responsive to lowering. So, it's important that we treat high blood pressure to prevent strokes. The other complications of high blood pressure are things like heart failure or heart attacks. Those are things that we can lower with controlling blood pressure. But then I think more and more we should be recognizing that high blood pressure is a major cause for chronic kidney disease. And with high blood pressure, people don't typically feel that they have kidney disease. It's something that pops up. Typically, if somebody has very severe and later stages of chronic kidney problems, high blood pressure affects all the organs in the body in some way. But most commonly we think about it for the brain, the heart and the kidneys.
TODD: Let's talk a little bit more about those guidelines. 120 over 80 being the desired, something under that. How hard and fast is that?
DR. PATEL: When we talk about what those numbers are, it's really important we ask ourselves, where did they come from? And that means how did we measure the blood pressure? Because those numbers are guidelines and we use that to kind of help our patients understand their risk for developing complications of high blood pressure, as well as helping to monitor so we can actually diagnose the condition. And there will be fluctuations throughout the day. And, so, it's important we understand how [was] the blood pressure measured? Where was the patient and how are they feeling at that time? So, we try to measure blood pressure in a standardized way. And then when we see that the blood pressure is consistently at that level, then we decide if it's high, normal or low. And, so, what I would typically recommend is to look at an average range of blood pressures. And if that average appears to be higher than 120 over 80, then we need to start talking about elevated blood pressure or hypertension.
TODD: Does blood pressure tend to just naturally go up as you age, say, are you more tolerant of someone's blood pressure starting to creep upward as they get into their later years?
DR. PATEL: Yeah, that's a great question we commonly get in the clinic. So, we know that blood pressure starts to increase kind of right in the early parts of young adulthood — once you finish high school, both the top and the bottom number. We also know that later on in life, kind of in that mid to later part of the adult life, instead of both numbers increasing the top number increases more, whereas that bottom number may not increase as much — and potentially may even stay stable or go down. So, the blood pressure naturally will go up as we get older in our adult life, whether or not to treat the high blood pressure or are we more tolerant to that high blood pressure? That's a conversation we have to have with our patients because we know that that higher blood pressure number, regardless of your age, is going to be linked to higher risk of stroke, heart failure, heart attacks and kidney disease — despite your age. Now, if I see blood pressure increasing — regardless of their age — I need to recognize that does increase their risk for complications despite their age. Whether or not we treat that to lower their risk for those complications is a conversation with the patient because there's some risks to lowering blood pressure too much, and there are side effects to the things that we do to lower blood pressure. And so we may not necessarily recommend the same thing for somebody depending on their age or other factors. It's really just making sure we're prioritizing what the patient wants.
TODD: Any differences by race or gender? I saw a recent study that found that women's normal range was lower and that perhaps the risk factor for them should be 110.
DR. PATEL: So, we know that blood pressure levels may differ across different racial or ethnic groups, as well as sex. But, in general, in clinical practice, we typically use the same definitions for high blood pressure. Now, whether or not their risk of heart complications, stroke complications, kidney complications differs, I would still recommend similar blood pressure control despite somebody's sex, racial or ethnic group.
TODD: So those guidelines changed. I remember when the news came down, I remember there being some skepticism out there that this was all a cabal by the pharmaceutical companies to get more people on medication. What was your view of that change?
DR. PATEL: So, in 2017, there was a change in the guidance from many different societies in the medical community as to what high blood pressure actually is, how we define it. So the definitions of high blood pressure changed and we say that somebody has hypertension or chronically elevated blood pressure when the numbers are more than 130 millimeters of mercury for the top number and more than 80 millimeters of mercury for the bottom number. The decision to treat those with medications, those also differed. And when we actually look, more people may have been diagnosed with high blood pressure in 2017, but the number of people who are actually recommended medications based off of those guidelines was not as dramatically increased. And that's because the treatment of hypertension also depends not just on the numbers of your blood pressure, but also your risk for complications. And so we're moving more towards a personalized approach for the patient, that we're not just treating the numbers but we're treating the individual based off of their risk factors.
TODD: It seems to me that this leaves kind of a small window which your blood pressure should be. Mine was always good, but occasionally it would drop down a little low and they would sort of call attention to that. But it was usually like 118 over 72. Now, like when it comes up — 122 I notice — it will say elevated risk. So, it's a pretty tight window now.
DR. PATEL: With every 1 millimeter of mercury there are some subtle increases in risk of complications. And, what I would say is, is the blood pressure should vary throughout the day. So, it depends if you're measuring it the same way every time and you notice that even when you measure it the same way every time, it's still starting to increase. Then we need to start paying attention to other risk factors. Did something else change, besides us just getting older. Whether or not to actually use medications or not, that's a different story. You know, blood pressure treatment, I would say, is about two thirds lifestyle and one third medications. And so perhaps there's a reason why the blood pressure started to increase that may just be able to be addressed with lifestyle changes as opposed to medicines.
[Music being to play to signal a brief interjection in the interview]
ZACH: Dr. Patel talks about the most common type of high blood pressure, what's known as primary hypertension. That is high blood pressure for which the cause is not known. It's thought to involve genetics, diet and lifestyle. Most adults with hypertension fall into this category, but there's a second type of hypertension less talked about. It's known as secondary hypertension. No difference in blood pressure ratings, but its cause is known: another medical condition. Examples include narrowing of the arteries that supply blood to your kidneys, adrenal gland disease, obstructive sleep apnea, hormone abnormalities and thyroid abnormalities. Unlike hypertension, secondary hypertension isn't characterized by obesity or family history. It can be characterized by very high blood pressure — say, 184/120 blood pressure that spikes before the age of 30 or after the age of 55 — and no response to blood pressure medications. Only about 5 to 10% of hypertension is the secondary type. If you have a condition that can cause secondary hypertension, you may need your blood pressure checked more frequently. Ask your health care provider how often.
[Music ends to signal return to the interview]
TODD: So, I know it’s referred to as the silent killer, but are there any signs or symptoms that are kind of giveaways that you might have a blood pressure issue?
DR. PATEL: Yeah, I think that's a really good question because of how common high blood pressure is. So, symptoms of high blood pressure can be vague. A lot of people don't even notice that they have high blood pressure and they go to their primary care doctor or and they just notice that somebody said that my blood pressure is a little high. And that's because the majority of people don't necessarily know or feel their high blood pressure. It's called a silent killer because, regardless of your symptoms, those high numbers are still linked to higher risk for the strokes, heart failure events, heart attacks and kidney problems. But some of the symptoms, too, that potentially could be caused by high blood pressure could be things like headache, blurry vision, just feeling tired, a little chest discomfort. So, it's important that patients talk with their doctors about these things, but the symptoms can be quite vague.
TODD: So, talk about the causes now of high blood pressure.
DR. PATEL: So high blood pressure, most commonly, is related to many things. It's hard to point out just one specific thing that's causing the high blood pressure. We talked about secondary hypertension. That's when we can identify a specific cause, like a narrowing of a blood vessel that supplies the kidney or hormones that are secreted by some of the tissues in the body. Those can cause high blood pressure. But most commonly high blood pressure is related to many, many genes. And in individuals who have a family history of high blood pressure, those patients may actually also be at high risk for developing high blood pressure. And that's just, in part, related to many, many different genes in the body. But then a major driver of high blood pressure, especially in the United States, is our diet and lifestyle. So, one of the major causes of high blood pressure is the amount of salt in our diet in our current society. We're on the go so much we're eating foods that may not necessarily be fresh foods — that could be processed — and there could be a lot of salt in those foods. And the type of salts that we're talking about are sodium salts. Those things lead to high blood pressure. Excess weight leads to high blood pressure, as well as not being as physically active. So, it's typically related to the genetics of an individual as well as many of their lifestyle factors such as weight, physical activity, diet. And, also, something that's being increasingly recognize is sleep. Sleep is extremely important to help keep your blood pressure under control.
TODD: Just going to the salt, people probably don't know that they're getting as much salt as they are. It's not like they're taking the saltshaker and putting it in food, but they're just getting it in a lot of processed foods where they're not aware of how much is really there?
DR. PATEL: Absolutely. I think that is a major point to make. So, in our average diet in the United States, it's estimated that maybe about three quarters of the salt that we eat is not what we're adding to the food ourselves. It's already in the foods. So when we talk about the salt in our diets, we have to be mindful of the actual packaged labeling, because a lot of those foods have salt and those are very common things that we see in the grocery store — like deli meats and many, many different foods, canned foods. The salt is not necessarily what you're adding to the food, but ends up, commonly, already being in it.
TODD: So, what should you aim for if you're reading packages? What should your daily intake be no more than?
DR. PATEL: The recommendation for the amount of salt for an average individual would be about less than two grams of salt. And when we talk about salt again, we're talking about that sodium chloride and that can be seen in found in lots of different things. And so when you're when you're reading the packages, you'll notice that anything that's processed — canned foods, deli meats, especially those things are going to have a lot of salts, even breads, things that you may not necessarily expect — you're going to have a lot of salt. And when you add up all of those things, it'll add up to above two grams pretty quickly.
TODD: And is there any other food that's a risk factor for high blood pressure?
DR. PATEL: So, we typically predominantly focus on the sodium chloride salts. The other thing that may be lacking in individual that can lead to high blood pressure is actually low amounts of potassium. And so that's why actually eating fresh fruits and vegetables can help with controlling someone's blood pressure. So, as opposed to having too much different salts with sodium, actually the absence of potassium can lead to high blood pressure. It could potentially could be help lower the blood pressure when you actually eat those foods, like tomatoes or bananas and things.
TODD: We've covered a lot of the basics of blood pressure. Up after the break, we dig deeper into how to prevent hypertension and how to manage it if you do have it.
TODD: How treatable is high blood pressure?
DR. PATEL: Blood pressure is a very treatable, modifiable risk factor for all of these cardiovascular concerns and kidney disease. Blood pressure is typically treated mostly with lifestyle changes and then medications. And it's really about, you know, two thirds lifestyle, a third medication. And so we can make meaningful, meaningful reductions in blood pressure levels just with changing certain lifestyle factors — especially because we know that rates of achieving certain goals in our life with those lifestyle factors are actually, there's a lot to be gained there. So, most adults in the United States are not achieving their physical activity goals. So physical activity — at least about 30 minutes a day on average, five days a week of doing some intentional activity — can help lower the blood pressure. Making sure you get about 6 to 8 hours of sleep a day, that can also improve your blood pressure. Cutting back on salts in the diet with sodium, that can also lower your blood pressure. Avoiding smoking, as well as moderate amounts of alcohol intake. All of those things can lead to dramatic reductions in blood pressure, such that you don't even need medications. And then, if you do need medications, we have various active medications that can lower blood pressure — that are generic medications and are typically more affordable than some of these newer medications that may still be on brand.
TODD: But these are what? ACE inhibitors?
DR. PATEL: ACE inhibitors are one example of medications used to treat high blood pressure. It's considered to be one of the first line medications. And within ACE inhibitors, that's a family of medications with lots of different medicines within that family. For patients who may have a cough with ACE inhibitors, there's something called ARBs. Those can also be used to treat high blood pressure. And there's two other kind of families of medications that we think about to lower blood pressure as a first line. And those are medicines that make individuals urinate, called diuretics. There are certain types of diuretics that we use to lower blood pressure. And then there's something called calcium channel blockers. Those medications can be used to lower blood pressure. So those are the kind of three major families, the calcium channel blockers, the diuretics and then we think about ACE inhibitors and those ARBs as kind of together.
TODD: And is there any downside from the medication, if that would be reason to try to prevent it? Are there side effects from the medication?
DR. PATEL: All medications have potential side effects. I would say that those classes of medications are typically well-tolerated. Most individuals do not experience side effects, but that's part of why we ask our patients to follow up with us in clinic so we can make sure we're counseling on what things to watch out for — whether it be some swelling in the legs or needing occasional lab checks to make sure that the kidney function, the electrolyte levels look okay. And some of those things you don't necessarily feel. So, there are certain things that have to be monitored. But, in general, we know that those classes of medications are very effective at controlling blood pressure. But probably as important, if not more important, in my opinion, is those medications reduce the risk of complications of high blood pressure.
TODD: And what's the latest on when's the best time to take them? Morning? Night? Is there much of a debate about that?
DR. PATEL: There's a lot of controversy actually in the medical literature right now about when to take medications for high blood pressure. This whole idea stems from the fact that there is a circadian rhythm and our blood pressure varies throughout the day. Typically, at night, the blood pressure will dip. We call it nighttime dipping, and then the blood pressure will start to increase as we are waking up in the morning. And there's a lot of data to suggest that there may be benefits to taking medications at one time versus another. And there were some initial studies that hinted at the fact that it may be more beneficial to take medications at night. But, you know, more recent studies actually suggest it probably does not matter. And I do not recommend my patients taking their medications at one time of day versus the other. The most important thing is that patients actually take their medications as prescribed, and if it's a once a day medication taking at the same time every day. So typically, what I recommend is take the medicine at whatever time you're going to remember. Because when we actually look at this a little bit more, there's no difference in if you take the medicine at night or in the morning.
TODD: And what's the best way to measure your blood pressure outside of your doctor's appointment? The home cuff devices, drugstore kiosks?
DR. PATEL: That's a very common question we get in clinic. So, I think there's a lot of benefits to home blood pressure monitoring. In fact, I recommend it for a lot of my patients who have high blood pressure. And part of that's because we know when patients come in to see us in clinic, there is a lot of activity that happened before that you had to go find a parking spot, maybe get in an elevator, get moved into the clinic room. So, it's important that when patients come into our clinic that they're resting for a few minutes before we actually measure blood pressure. And so those blood pressures vary due to all of these different stimuluses around them. And so typically, I recommend patients actually measure their blood pressure at home where things are a little bit more stable, calm. And I typically recommend if using a monitor and blood pressure at home, number one, to have a validated blood pressure device. There's a simple website called validatebp.org. They have a list of blood pressure cuffs that are actually approved for use and validated. They've been tested to be accurate. And there's a whole range of blood pressure devices that can be used, some that are very fancy with different technologies like Bluetooth connections to phones and all kinds of stuff, and then more simpler devices. And, so, the cost varies quite a bit, but making sure, number one, that you have an appropriate blood pressure device. And then, number two, when you're measuring your blood pressure, I typically recommend to measure it first thing in the morning. And that's in part so that we have a consistent average because most of us wake up around the same time each day. And, number two, you're able to do it in a systematic fashion. And I typically recommend you should have your blood pressure measured after you've emptied your bladder, because having a bladder full could increase your blood pressure dramatically. Both feet should be on the ground and you should be resting for about 5 minutes before you measure that blood pressure. And then you measure it and keep a log. And we commonly give patients a paper log or then there are other options you can keep an electronic log on your phone or computer or however you like. And then consistently measure it the same way multiple times per week, every day or five days out of the week. And then we can get a consistent average having a morning blood pressure reading, as well as an evening blood pressure reading right before bed can be very helpful. But as long as we're getting it on average about the same time, that's much more helpful because then we're seeing what your blood pressure typically is. And there are differences in blood pressure when you measure it throughout the day, as well as if you're in the doctor's office or not. So, there's a common syndrome that we talk about called white coat hypertension. That's when your blood pressure is typically normal at home but elevated when you come to see the doctor. But we're not going to know if you actually have white coat hypertension or if you just have hypertension if we're not getting those readings outside of the doctor's office. And then there's the opposite. There are people who have elevated blood pressure at home but who have normal blood pressure at the doctor's office. And so that could be a concealed high blood pressure.
TODD: I can understand getting nervous for a doctor's appointment [to cause it] going up. But why would it go down when you go to the doctor?
DR. PATEL: We actually don't know why that happens. We also don't know why people have white coat hypertension — the opposite. Some people think that it may be related to stress, but that's probably not the case. The white coat hypertension is commonly seen in people who don't even feel stress or have any changes that may stimulate them. And so we're not entirely sure why there are individuals who have white coat hypertension or that kind of masked high blood pressure.
TODD: Those home devices are easy to self-administer and read?
DR. PATEL: So those home blood pressure devices typically have instructions on how to use them and — we talked about the positioning and the rest before — but what's really important for patients to recognize is that the size of the blood pressure cuff matters a lot. So, for individuals who have larger arms, the circumference of the arm is large, they're going to need a bigger cuff size. And, so, there's typically markings on those blood pressure cuffs as to where those straps should lie once fastened to the arm. Similarly, there are individuals who have smaller arms and their arm circumference may be small. Those individuals need a smaller cuff size. And again, the markings on the blood pressure cuff will help in terms of putting the device on. Then typically those devices are automatic blood pressure devices. When you press the button, the cuff will start to inflate and then you'll get a reading. Typically, those devices have very large displays where you can get the blood pressure readings. Some will generate averages over time, some you'll have to write down yourself. But in general, they're pretty well-designed devices. But again, the important thing is that it's a validated blood pressure device.
TODD: And how about those drugstore kiosks? Are those reliable? I never know how much faith to put in them.
DR. PATEL: That's a great question. I think those blood pressure kiosks are helpful to give a general sense about your blood pressure, but there are lots of limitations to them. Number one, you're in an environment where you may not necessarily feel as comfortable. There's lots of things going on, so being able to sit there for 5 minutes at rest, to get a stable blood pressure reading is challenging. And then the cuff size is typically one. There's a one cuff on those devices. And, so, in general, I don't necessarily think those are great ways to measure blood pressure because you may not necessarily have the right cuff size as well as being able to rest.
TODD: We talked about how your blood pressure is variable during the day. So where are they on the move toward continuous monitoring? And how much of a need is there for that?
DR. PATEL: So, I think continuous monitoring is important for select individuals. For the average patient, for hypertension, I don't think the continuous 24-hour monitor is necessary. For select cases, such as individuals who may have some neurologic diseases, that's where 24-hour blood pressure monitoring can be very helpful, because with certain conditions there can be very large fluctuations in blood pressure and commonly that's related to nervous system issues. So, in general, I don't necessarily think the continuous blood pressure monitoring — where the device is hooked up to you for 24 hours — is necessary for most patients.
TODD: Do you nonetheless think that 50 years from now there will probably be something that everybody wears that's unobtrusive? Or that we'll be doing that?
DR. PATEL: There are some really interesting technologies that are being developed where you can measure what we call hemodynamic parameters — or really things like pressures in the body, like blood pressure. I think those devices are becoming more and more accurate, as well as give us a very good understanding of the individual person's data. The question that I always ask is what are we going to do with that information? And it may be helpful, but I think we need more data to actually know if that data is helpful because it could be potentially a nuisance to patients.
TODD: That's about it for me. Is there anything you want to add to end this one?
DR. PATEL: Yeah, I think one thing that I don't want patients to get discouraged by is when a physician's ordering blood pressure lowering medications, sometimes we commonly give patients not one, but two medications. And that's because what we've learned over time is that using multiple medications at lower doses is probably more effective at lowering blood pressure with less side effects. So, if you notice that your doc is giving you multiple medications and you're saying, “Hey, doc, my blood pressure is not that high.” It's important to ask the question why? And it is possible that's because they're trying to get you on multiple lower doses of medications to avoid those side effects from medications, while effectively lowering your blood pressure. So, I also think it's important that patients know you can always, always work on lifestyle changes to improve your blood pressure, so you can potentially avoid blood pressure lowering medications or potentially using less of those medications.
TODD: All right. Very good. I appreciate you coming here. I learned a lot. Thanks again for being here.
DR. PATEL: Thank you so much for having me.