HLOL Podcast Transcripts

Health Literacy

Blood Testing: What Is Learned in the Lab (HLOL #223)

Helen Osborne: Welcome to Health Literacy Out Loud. I’m Helen Osborne, President of Health Literacy Consulting, founder of Health Literacy Month and author of the book Health Literacy from A to Z. I also produce and host this podcast series, Health Literacy Out Loud.

Today, I’m talking with Dr. Parul Bhargava, who is Professor and Vice-Chair of Laboratory Medicine at the University of California, San Francisco, or UCSF. Dr. Bhargava is a pathologist with subspecialty training in hematology. She describes herself as passionate about medical education and has authored or edited numerous academic publications.

Parul and I are both members of the Advisory Board for something called The Blood Project. I interviewed her for their podcast series called “Talking About Blood.” She shared so much great information that I asked her to be a guest on Health Literacy Out Loud.

Welcome, Parul.

Dr. Parul Bhargava: Thank you, Helen.

Helen Osborne: Health literacy is about communicating health information in ways patients and the public can understand. But your job, you’re in a lab somewhere. I don’t know if you’re directly talking with patients. We need to know what happens in the lab there when we are communicating.

Can we just start by putting this into context? What is diagnostic testing? What is lab medicine? Are they all the same? All I know is I get sent by my health plan down to the lab and they take blood. What happens at your end of things?

Dr. Parul Bhargava: I like to talk about lab services as a core function of any healthcare facility. It is similar to, say, radiology where you get imaging done. That’s also another core function.

When I say core, I mean that they are essential backbone that any hospital needs to have, and they service many specialties all around them.

It’s sort of like my analogy to a tree, where they are the trunk.

Helen Osborne: The blood is the trunk? The tree is the trunk? The pathology is the trunk? Who’s the trunk?

Dr. Parul Bhargava: The pathologist or pathology services and lab services are the trunk of the tree of medicine.

When you study medicine as a whole, which is the study of human health and disease, your foundation, or the roots, is knowing what normal is like. What is normal anatomy of the body, normal physiology of the body? That is where you start out. Any student of health would start out there, which would be the roots.

The trunk is the connector between health and then disease. It’s telling you when things go abnormal. Then what happens? How does the body change? How does it react? How does it look different or feel different or is chemically different?

Then come the branches. Then you dive deeper into one area. Maybe just the heart, the gut or the brain. Those are all the branches that ultimately all rest in the study of disease, which is the trunk, which is pathology.

Helen Osborne: I’m fascinated by that. I think of you a lot. I’ll probably share some more stories of how and when I think of you and the work that you do with pathology and investigating about our blood.

When I hear about this tree, I’m from Massachusetts and I have this image of sap running through a tree, our maple trees. Then come the early spring, you’ve got all these buckets gathering the sap, and then someone will boil it down to make something tasty and yummy. Is there any equivalent to that fluid running through the tree like there is to maple syrup?

Dr. Parul Bhargava: Absolutely. That fluid is blood. Blood has to traverse practically every littlest cell of the body. It is going back and forth carrying nutrients up and down, carrying waste products out. The blood is really the essence or the sap of life.

Helen Osborne: Interesting. I also thought of you yesterday. I just had my regular old checkup. I guess it was time because the doctor told me I needed this blood test and that blood test and whatever. She did her paperwork, and then I went down to the lab.

Before I got to know you a little bit, I might have thought, “Really? I can’t just go? I have to now wait to get my blood drawn?” Then they can’t even find my veins.

But after talking to you about all that can be learned from the blood, I had a very different appreciation of that process.

Can you clue in listeners and all of us what happens when someone goes to get their blood drawn? What can you be learning about that sap of life in there?

Dr. Parul Bhargava: Absolutely. If you’ll let me digress a little, I want to draw another analogy.

Let’s say, since we’re in COVID times, that someone was quarantined because they had COVID and they are stuck in their house. But they need things to come back and forth from the house. They need electricity and water. They might have a FedEx delivery. They might have friends come drop off food. They might have the trash guy come pick up the trash.

Imagine all those things coming in and out of the house and going through the roadways out. Blood is doing all of that, where the house is every cell of the body. Everything that comes in and out is the blood. It is not only carrying food, nutrients, water and things into the house, but it’s taking away things, so trash out.

It’s also the cop car. It’s a policeman coming there, checking in and making sure that there are no unscrupulous elements floating around, meaning things like infection when it comes to the body.

Helen Osborne: You are a fabulous storyteller, and your images just really stay with me.

As isolated as someone might feel if they’re stuck in their house and can’t go anywhere, you’re telling me there’s a whole community or a whole group of things that happen even though we’re not aware of that.

I want to hear a little bit more about what you really learn about our blood when we go there. I had routine screening. The doctor checked a whole bunch of things. They had to take two different bottles of blood. They did whatever they did, and then I opened my patient portal and I found the results.

That was a routine screening, so there’s really nothing particularly wrong with me. What are you looking for? What does someone look for in that kind of a blood test?

Dr. Parul Bhargava: Again, to give a broad overview of what components blood has, the blood is a very complex system in which there is a liquid component, which is comprised of water, but floating in the water is a lot of proteins and chemicals.

Then there are cells in there. There are three different types of cells. One is called the white cell. That’s like the policeman that is looking for any signs of infection or things around that they need to tackle before they get out of hand.

Then there are the red cells that are carrying oxygen to and fro to every cell, which is the energy needed for any cell to survive.

Then there are platelets that are looking for any leaks in the tubing, and they’re sealing off those leaks if they occur. Let’s say you bump your hand and break a little vessel. The platelets would come seal that.

There are these three types of cells as well as all the proteins and chemicals floating in the liquid part. That’s all in blood.

Basically, the blood is actively responding to any changes happening in any part of the body. If someone has a toothache and there is an infection there, the white cells will get recruited there to tackle the bacteria that are there.

You can get a blood test for two reasons. One is that there is some symptom that you present with and the doctor is trying to get a head-start and figure out what’s wrong.

Let’s say someone has a tummy ache or someone has a fever. A blood test would be the first step in trying to figure out what’s going on.

Then you could have routine tests, like the one you did. In that case, there are certain changes that can happen in our blood which don’t necessarily cause symptoms in that moment. But if left unchecked for a long time, then they can lead to problems downstream.

If I can explain that with an example. One of the routine things that people look for is cholesterol.

Helen Osborne: I can relate to that one. Had that one yesterday. I’m sure I’m getting a follow-up call soon. Go on.

Dr. Parul Bhargava: Cholesterol is a type of lipid or fat that is normally present in everybody. But if you have too much of it and if it’s too high for too long, it can lead to problems like heart disease.

As it’s creeping up, it can be completely asymptomatic. People will often screen and look for that to see if they can nip it in the bud, so to speak. If it’s too high, they can suggest changes to your diet or activity or sometimes prescribe medication so that you keep it at a reasonable level.

Helen Osborne: Thank you. As I said, I thought of you when I was getting my blood drawn yesterday. I had my blood test, and then a few hours later, the results were on the patient portal. What kinds of machines or evaluations, or when I leave, what happens in the lab?

Dr. Parul Bhargava: As you mentioned, you got two different types of tubes drawn. There are many different types of tubes, firstly, that you can get your blood drawn in. The reason for that is it depends on what we are trying to assess.

Are we looking at the cells, or are we looking at the liquid part, or are we looking at chemicals that tend to degrade easily so we need a different preservative in the tube? That’s the reason why you have different types of tubes.

Those different types of tubes are often identified by the color of the cap that they have. You might notice next time that there’s a lavender cap on some, green on some and red on some. That’s standardized worldwide. A red cap would always mean the same thing across the world.

Once you have all those tubes drawn, the next thing that needs to happen is they need to be transported to a central facility, which is the lab where all the instrumentation to measure different things in the blood are present.

We control this aspect of it also closely. How much time does it take to be transported? At what temperature? Some of those things can affect the composition of blood.

Then once it reaches the lab, there’s usually a computer system in which we can log in the patient so that we know we are constantly tracking that this tube belongs to this person. We have different identifiers.

Once that happens, then they go on to the machines. There are many types of machines that exist in most labs. There are some that are looking at the proteins, some that are looking at the chemicals, some that are looking at the cells, what their number is like.

Usually, the first step in the lab after it’s been logged in to our computer system is it goes through one or more machines, and all these numbers get generated depending on what you’re trying to analyze.

Helen Osborne: Do they need much blood for that? The tube was a couple inches long. Do they need a whole bunch of blood to do that?

Dr. Parul Bhargava: No. In fact, it’s amazing how much information we can get from a few milliliters of blood. A typical tube that we draw in an adult is somewhere around four to four-and-a-half mLs, or milliliters, of blood that is drawn. Just to keep it in context, most adults have about five liters of blood. You’re really taking a very tiny amount.

Then from that one tube, we are often able to run multiple tests. Each assay might only take about 100 to 200 microliters to run. We’ve become really sophisticated in our technologies these days, and it’s amazing how much information can be generated from just a small drop.

Helen Osborne: When I got the results back, I got four different notices of, “Your lab tests are back.” One of them must have listed six or eight different things. Then some of the other ones didn’t list as many.

I had this image of what goes on there. I don’t want to be speaking like I’m really naïve. I used to work in healthcare. But I just had the sense you’re looking under a microscope or spinning things around. I didn’t know until I saw a picture of you in front of some of the machines really what’s happening. These questions must be so basic for you, but it’s hidden from me as the patient.

Dr. Parul Bhargava: Yes, but there’s a whole team that’s actually looking beyond the machines. Blood testing is not simply putting the tube in and getting a number out from a machine. There’s a whole team of people working.

Just at UCSF, for example, I have 450 people who are working only in the lab.

Helen Osborne: Really? Oh my goodness.

Dr. Parul Bhargava: Yes.

Helen Osborne: You mean the people we as patients never would see, right?

Dr. Parul Bhargava: That’s right. They are looking at different aspects of it right from the point of the person who’s actually drawing your blood to the person who’s sitting at the computer. But then a whole team of them who are at the machines.

The machines have to be calibrated. They run a lot of quality checks every day, sometimes every eight hours. We want to make sure that the machine is working perfectly.

But that’s not all that they do. They look at every result that comes out of the machine.

There are things that can go wrong sometimes. For example, there could be a small clot that had actually clogged the tubing of the machine, so the result may not be valid.

There are things like that that the technologists who are there are trained to look at all these errors, and then repeat the sample if necessary, or check for any interferences.

Sometimes patients have derangements that can impact the assay. For example, if their lipid or cholesterol level is too high, or let’s say they are jaundiced, those chemicals can interfere with measurements of other things.

The technologists are all scientists who are trained to look at all these things as a whole.

Then they will only release that number to the patient’s chart once they’re satisfied that the machine worked properly, the quality checks were all passed and there was nothing specific to that sample that could have caused an erroneous result.

Helen Osborne: I keep learning so much from you, and I mean that so sincerely. I really had no idea. Four hundred and fifty people are doing this.

Now you’ve got these machines, your scientists, your technicians. You know so much about this. How did they diagnose disease years ago before we had all these fancy machines?

Dr. Parul Bhargava: It’s really come a very long way, Helen. For example, let me start with a simple issue, like someone was feeling tired. They’re tired because they’re anemic, which basically in medical speak is that they have low hemoglobin, which is the molecule that carries oxygen that lives in red cells.

If we were talking about, say, 100 or 200 years ago when we didn’t have these sophisticated ways of diagnosing, people might have said, “They look weak and pale.” Maybe they need to eat certain types of foods they might have learned from trial and error. That might help them. They would maybe give them some general tonics and such to improve.

Then some patients would improve and some may not improve. Ultimately, they didn’t know what was causing the problem.

Fast forward to today, we can not only run the blood and, firstly, say, “Yes, your red blood cells are low,” or, “Your hemoglobin is low,” but we can go so many steps beyond that.

We can look at the shape and size of the red cells under a microscope, and then we can say what type of anemia it could be. What is the reason? Why are the red cells low?

Then we can go more targeted and go treat the exact cause that was causing it. Is it really iron that was low in the patient, or is it another vitamin like B12 that’s low? We can actually measure those levels now chemically.

Helen Osborne: Wow. I hope the listeners are learning as much as I am by this, because I am learning a lot from you about what happens.

Now we’re bringing it to the present day. Our listeners, I am, all of us are interested in health communication. What would you like us to be able to say to our patients or the public about blood tests? Is there just a simple way to be able to talk about that?

You’ve provided so many stories, analogies, metaphors and all of that, but how can we clearly help others really appreciate what happens with blood tests?

Dr. Parul Bhargava: A blood test is an easy way, if I put it in context, to get a window into what is going on inside the body to the deepest, darkest parts of the body that we otherwise would not have reached.

The blood will carry the message from the area that is diseased or abnormal, and we will be able to analyze that and give a more specific, tailored diagnosis to the patient.

We can tell, “Not only is this wrong, but it’s wrong because of this.” Not only is it wrong because of this, we can now go even more sophisticated and there are certain tests that will tell us whether a particular medicine would work or not work.

Helen Osborne: Really?

Dr. Parul Bhargava: You can go even beyond that. Let’s say someone had some disease. There are markers that will tell us how the disease might behave in the future. There are prognostic markers as well that we can assess.

It spans the gamut from not only diagnosis but targeted treatment and future state, and also response to treatment.

Helen Osborne: I hear your excitement about what you’re doing. In the beginning, you said you were passionate about some of this, and I can hear that passion and conviction. I’m getting some of it.

I just want to thank you for all you’re doing and for telling us what happens beyond, but really giving all of us a window not just into what happens in our body and how blood does that, but really a little peek into what happens in the laboratory that we on an everyday basis would never be seeing.

Parul, thank you for all you do and for sharing it with us on Health Literacy Out Loud.

Dr. Parul Bhargava: It was a pleasure, Helen. Thank you for having me.

Helen Osborne: As we just heard from Dr. Parul Bhargava, it is important to communicate about all parts of our body. Not just the things that we know, see, touch or do, but even all that happens behind the scenes, such as with pathology and lab medicine. But communicating clearly about health certainly is not always easy.

For help clearly communicating your health message, please take a look at my book, Health Literacy from A to Z. Feel free to also explore my website, www.HealthLiteracy.com. You’re welcome to contact me directly at helen@healthliteracy.com.

New Health Literacy Out Loud interviews come out every few weeks. Get them all for free by subscribing at www.HealthLiteracyOutLoud.com, or wherever you get your podcasts.

Please help spread the word about Health Literacy Out Loud. Together, let’s tell the whole world why health literacy matters.

Until next time, I’m Helen Osborne.

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