What do you know about the numbers that get read out to you after you get your arm hugged by a blood pressure cuff? Nearly half of American adults have high blood pressure. And because there are no obvious symptoms, many people don’t even know it. Cardiologist Nicole Bhave, M.D. joins us to sort out answers to the most searched questions about the “silent killer” that is high blood pressure.
- What is “good blood pressure”?
- What causes high or low blood pressure?
- How can someone lower their blood pressure?
- Can COVID affect your blood pressure?
- Is it a good idea to monitor your blood pressure from home?
Find out what the numbers mean and what you need to know about blood pressure in this week’s episode of the Michigan Answers podcast.
More resources
Transcript
Dr. Preeti Malani:
140 over 90, 120 over 80. If you're like most people, you aren't quite sure what to make of those numbers after your arm gets squeezed with the blood pressure cuff. But the facts remain that nearly half of US adults have high blood pressure. And what's a little scary is that many people don't even know they have it. There's a reason high blood pressure's often been called the silent killer. Most of the time, there are no obvious symptoms. So what do we know about high blood pressure? Today, we're going to talk about the most searched questions about blood pressure and the answers to those questions are coming to us straight from Dr. Nicole Bhave, a cardiologist at the University of Michigan Health Frankel Cardiovascular Center. There may be a confusion about blood pressure, but fortunately, there are a lot of things you can do to manage your risk. So let's get started.
Dr. Preeti Malani:
I'm Dr. Preeti Malani, thank you for joining us on the Michigan Answers podcast. Hi Dr. Bhave, thanks for joining us today.
Dr. Nicole Bhave:
Thanks so much for having me today, Dr. Malani.
Dr. Preeti Malani:
Okay, you know how this works. We take a topic, in this case, we're talking about all things blood pressure, and I'll ask you some of the most frequently searched questions about the topic.
Dr. Nicole Bhave:
That sounds great.
Dr. Preeti Malani:
This is going to be fun and we're going to learn a lot. Are you ready for question one?
Dr. Nicole Bhave:
Absolutely.
Dr. Preeti Malani:
First question. What is good blood pressure?
Dr. Nicole Bhave:
That's an excellent way to start. So first of all, I just want to explain how blood pressure is measured and what the numbers mean. So the top number is called the systolic blood pressure, that's the pressure in your arteries when your heart is squeezing or contracting. And the bottom number is called the diastolic blood pressure, and that's the pressure in the arteries when the heart is relaxing. Normal blood pressure is currently defined as less than 120 over 80 millimetres of mercury. It's important to keep in mind though, that this number is a true resting blood pressure, taken when you're relaxed and you've had a few minutes to sit still. But we don't base a diagnosis of high blood pressure or what we call hypertension, on just one reading. If several readings are taken at different times and they average higher than 130 over 80, that would support a diagnosis of high blood pressure.
Dr. Preeti Malani:
Yeah. And this is interesting because that number has changed, that systolic blood pressure. We used to talk about 140, and now, as you mentioned, 130 is a better cut point.
Dr. Nicole Bhave:
That's right. The criteria have become more stringent over time, in order to help minimize cardiovascular risk.
Dr. Preeti Malani:
So next question, what causes high or low blood pressure?
Dr. Nicole Bhave:
So as you mention, high blood pressure is an extremely common problem in this country, and throughout the world. And some of the most common contributors to high blood pressure are being overweight, being sedentary or inactive, drinking too much alcohol, having obstructive sleep apnea that's not treated, and smoking. Many patients also have a family predisposition to high blood pressure. For some people, eating too much salt can be a factor. Low blood pressure, on the other hand, is a less common problem. Many young, healthy people will have blood pressure readings that you might think of as being too low, like 100 over 70 or 90 over 60, but these can actually be normal in young, healthy people. Both high and low blood pressure can be caused by hormonal problems, such as problems with the adrenal or pituitary gland, and problems with the nervous system.
Dr. Preeti Malani:
So your point is well taken, is that this is a very normal condition. In fact, some of the numbers I saw it's about 45% of all adults, and obviously that number is higher with older age groups. So how can someone lower their blood pressure?
Dr. Nicole Bhave:
The first thing we always recommend for patients who have high blood pressure is healthy lifestyle habits. Engaging in regular exercise, maintaining a healthy weight, avoiding smoking, and getting a good night's sleep. One of the great things about this condition is that it's so modifiable based on your habits. So for instance, if you're overweight, losing a modest amount of weight, about 5 or 10% of your body weight can have a big impact on your blood pressure. And I've had patients who have lost weight and have actually been able to stop some of their medications, which is wonderful. If you minimize your intake of processed foods, which are high in salt and eat plenty of fresh vegetables, that can also be really helpful. If your blood pressure's still high after these kinds of lifestyle changes, we usually end up recommending medications. Most patients actually need two or more medications to control their blood pressure adequately. And these medications come from several different families, including ACE inhibitors, calcium channel blockers, and diuretics.
Dr. Nicole Bhave:
At the beginning of the COVID pandemic, interestingly, there was a lot of discussion as to whether ACE inhibitors, and a related class of medications called angiotensin receptor blockers, could actually be harmful in COVID because they affect the way the virus enters cells. But now, later on, several studies have shown that these medications are not harmful in the setting of COVID and may actually help people who have COVID.
Dr. Preeti Malani:
So you brought up COVID and blood pressure, and that's actually one of the questions that's been searched a lot. And I don't think this will come as a surprise to you, but can COVID affect your blood pressure?
Dr. Nicole Bhave:
Absolutely. So any infection can cause stress on your body, and thereby affect your blood pressure. For instance, if you're having symptoms like shortness of breath or you're coughing, your sinuses are congested, just that discomfort alone can cause your blood pressure to be high. For most people, this is something that will get better as they recover from COVID. Low blood pressure, on the other hand, can be caused by dehydration, which is common if you have a poor appetite, or not drinking enough when you're sick and you have a fever. But if you're at home with COVID and you're feeling lightheaded or dizzy, it's really important to get in touch with your doctor because this could be a sign, not just of dehydration, but of other problems like heart muscle weakness or arrhythmias.
Dr. Preeti Malani:
Yeah, it's interesting. We think of COVID as a respiratory illness, but it also has a profound effect on the blood vessels. We're still learning, a couple years into this.
Dr. Nicole Bhave:
That's absolutely right. And as I'm sure many of you know, there's this phenomenon of long hauler syndrome or post-acute sequelae of COVID-19, that we're now calling PASC, and one of the features of that syndrome for some people is low blood pressure and fast heart rate. With it can be associated with dizziness and heart racing sensation. We're really still learning about the best ways to treat these symptoms, but some of the strategies include drinking large amounts of fluids, eating more salt and engaging in seated forms of exercise like rowing or using a recumbent bicycle.
Dr. Preeti Malani:
So this is a common question. What do you tell people if they ask if they should be monitoring their blood pressure at home?
Dr. Nicole Bhave:
I recommend home blood pressure monitors for most of my patients with the diagnosis of high blood pressure. And for some patients with a history of heart disease or diabetes, since good blood pressure control is an important means of preventing heart attack and stroke in those conditions. Especially for my patients who only come to the office once or twice a year, a home monitor is a great way to help us understand whether their blood pressure is consistently controlled over time. The monitor should be checked in your doctor's office to ensure that it's accurate. And when you check your blood pressure at home, you should follow a certain technique. Before you take your pressure, as I mentioned earlier, you want to make sure that you're completely relaxed for about five minutes, with your feet flat on the floor. Your arm should be at about the level of your heart and completely relaxed. You should ideally take two or three readings, separated by a minute, and your true resting blood pressure is the average of those readings.
Dr. Preeti Malani:
Yeah, I'm sure that people come to you with all types of spreadsheets and readings, and probably are sharing some of those readings with you between visits. So it can be, as you note, a very useful tool to really get a sense of how much medication is needed to get to that goal blood pressure.
Dr. Nicole Bhave:
Absolutely. And when I make medication changes, I often have patients track their blood pressure at home for a week or two, and send us their readings over our patient portal so that we can review and ensure that everything is looking good.
Dr. Preeti Malani:
Well, Dr. Nicole Bhave, we're so grateful for your time with us today. This was really helpful.
Dr. Nicole Bhave:
Thank you so much for having me, it's my pleasure.
Dr. Preeti Malani:
Thank you for listening to this week's episode of Michigan Answers. If you enjoyed today's episode, please subscribe wherever you get your podcasts. This season, we're unpacking some of the most searched for health topics on the internet. And if you're interested in learning more about how Michigan Medicine is improving lives and advancing health, you can visit us at michigananswers.com. See you next week.
Listen to more Michigan Answers podcasts - a part of the Michigan Medicine Podcast Network.
