Minding the Borderlands

Mark Koester (@markwkoester) on the art of travel and technology

Know Thy Blood: Common Questions and Answers About Blood and Blood Testing

Think of blood tests like a scoreboard.

On the one extreme, your lab results can help tell you and your doctor if you have a disease and they can give you early warning signs of future health problems. Blood testing get used throughout treatment to check on your responses and measure any side effects.

At the other extreme, biomarkers and blood tracking in general can indicate areas that are ok but not optimal. These tests can provide feedback on how to optimize towards improved wellness and longevity. If you are like me, then you can use your blood biomarkers to guide your health towards not just normal but optimal health.

There are a ton of reasons for regular blood testing. And, not surprisingly, blood testing has becoming a popular tool for self-trackers, biohackers, athletes and anyone striving for improved health in general. In my opinion, blood testing should be something everyone does regularly.

In this on-going series of posts on blood tracking and biomarkers, we are looking at how blood tests and other biomarker data can be use to to help self-trackers and people in general understand their health.

Unfortunately, blood testing, tracking and biomarkers can be quite confusing. Frankly most stuff in the medical space is rather intimidating. Almost intentionally so. There are hundreds of terms and a never ending range of opinions when it comes to our health. Fortunately, I think a basic and useful understanding of blood testing can be grasped relatively quickly, especially with the help of technology.

In this post, I want to answer many of the common questions about blood, blood testing and tracking, The first part focuses on questions like what is blood, what is a blood test, and how often to get your blood tested. In the conclusion, we will look at an initial answer to the most important question: Which blood tests you should get? Hopefully by the end of this post you should have a basic understanding of your blood and on how to get started with your blood tracking.


Dude, I’m not a doctor. If you aren’t sure, ask a real one. This post is not meant to be taken as professional medical advice. This is strictly my observations and opinions on what matters and doesn’t. While a lot of research and experimentation has gone into this, please seek professional medical advice along with your own personal research before doing anything stupid. Now on with the show.

Definitions: A Q&A on Blood Testing:

Besides just doing the tests and your doctor telling you that you are “normal,” you should also know the gist about your blood and blood testing in general. For example, what do these biomarkers signal, blood ranges, and what your blood test results mean. Before we can effectively track our blood and our health, we need to know a bit more about our blood biochemistry.

What is Blood?

Your blood is a fluid mix of of cells and lipids. It’s a collection of living cells and material. Blood’s primary function is to transport nutrients and oxygen to and from the cells as well as remove metabolic waste products. Your blood also detects foreign bodies and handles immunization, delivers messages through hormones, and regulates body temperature.

Blood mostly consists of plasma, which the primary fluid aspect of blood and makes up 54% of the blood’s total volume. Blood also contains a mix of proteins, glucose, minerals, hormones, carbon dioxide and blood cells themselves. Amongst the blood cells, the biggest number are red blood cells (RBCs), which make up 45% of blood. Additionally you have white blood cells (WBCs) and platelets.

Why Should I Get My Blood Tested?

While there is a lot of hype around blood testing, especially at-home blood testing using merely a pinprick drop of blood, much of these technological advances remain unrealized. For now the best and most reliable method remains traditional blood testing. But why should you get a regular blood test?

As I went in depth in Benefits of Blood Testing, advantages include: being a reliable measure of your health and wellness; diagnose disease; checking metabolism, liver condition, kidney function and even hormonal patterns; establishing risk of coronary artery disease and stroke; and even knowing if you have elevated information.

All of these help you spot trends that might lead to more dangerous health situations later. You can address small imbalances before they become larger problems.

Ultimately I find the key benefit is comes from the fact that your blood along with your nervous system are your two primary internal communication systems. This means that certain indicators in your blood are communicated in your blood. As such, your blood can become your health yardstick, telling you a lot about yourself.

How do I get my blood tested? What’s a Blood Test?

Most blood tests are ordered by medical professionals like doctors and clinicians. Many times blood tests are included with regular check-ups. Increasingly though there are companies and services that allow you to get your blood tested directly. For example, LabCorp is one of the most common providers of lab tests in the United States, and you can directly order the tests you want through a company like Life Extension or Quest Diagnostics.

What’s a Blood Test? What does it involve?

A blood test is a laboratory analysis performance on a sample of your blood. Blood samples are usually taken from the vein using a needle, though some blood tests like glucose can be done using a simple fingerpick.

Depending on the blood test you are getting, you may be asked to not eat before the test. This allows you to test your blood in a fasted state.

In general, blood tests are simple and fast. A nurse will clean your arm before injecting a needle into your vein. Then in a couple of minutes they will fill a few vials of blood. These are then used to run chemical analysis of your blood. While some blood tests look at a single component, many times blood tests are grouped into panels that check a range of biomarkers, like the basic metabolic panel or a complete blood count.

How Do Blood Tests Work? What’s the process?

After your blood is taken, the sample will be labeled before it gets processed by a lab. Some tests can be done on site, while others might require an off-site label for a particular screen.

Most blood tests break down your blood into different parts and then measure the constituent pieces. These specific measurements are then compared to established ranges in order to know if you are within the normal range or not. Different blood tests reveal different biomarkers, so you can use to understand your body and its organ systems in targeted ways.

For more on the science of how blood test analysis is done, check out Coulter Principle and Counter.

What is a Biomarker?

The term “biomarker” is short for “biological marker,” and it stands for anything measurable that can indicate something about our health. Biomarkers act as an indicator of the presence (or absence) underlying disease states. On an individual level, they also act as benchmark to one’s optimal health but also as a way to measure the effectiveness of a new drug or therapy.

There are hundreds of biomarkers, but a few notable ones include: LDL Cholesterol, Blood Pressure, Heart Rate Variability (HRV), Vital Capacity, VO2 Max, etc. Each of these can be used to understand your health status and predict risk of certain diseases.

If you want to dig deeper, I’ve created a dedicated post on What are biomarkers? as well as as an summary of the most common blood biomarkers.

How Often Should I Get My Blood Tested?

Depending on your health situation, most healthy individuals can benefit from getting their blood tested between two and four times a year. But even a yearly blood and healthy check-up can be beneficial. Your blood cells are entirely replaced every two to three months, which means, excluding a few indicators like glucose, you won’t see changes overnight in your blood working. Following a lifestyle change (diet, exercise) and certain supplements and medication, you will see potentially changes in your blood biochemistry within several weeks or months. Doctors regularly order blood testing when treating their sick patients.

How Many Blood Tests and Biomarkers Are There?

Thousands! In researching about blood tests and compiling a database of common biomarkers, I was surprised by just how many lab tests exist, especially for your blood. There are literally thousands of possible blood tests.

For the common blood tests and biomarkers, I found that there are well over 100 items, and The Mayo Clinic’s Rochester 2017 Interpretive Handbook of Medical Tests is over 2300 pages long and contains over a thousand examples of lab tests on your blood. This is a lot of potential blood tests, and more and more biomarkers and blood tests are appearing.

How Do I Read My Results?

Blood testing can seem quite technical and jargon filled, but reading your lab results isn’t that hard. Your blood results are compared to a simple reference range, which a statistical average of previous blood tests and what is a normal range. All you need to know initially is if your result falls within the range of normal. If it doesn’t, is it low or high and possibly what does that mean?

If you are looking for a good general introduction to reading your blood work, checkout Dr. Joe Brown’s YouTube Video, “How to Read Your Blood Work and Labs”.

How Do I Track My Blood?

While not ideal, most people I know track their blood results using a spreadsheet. At present, I’ve yet to find any great tools to compile and track your blood work. A few companies offer blood testing and help you interpret and contextualize your blood test results. Fortunately I have two options to help you track your blood:

Google Sheets Blood Tracking Template: Spreadsheets in general are a great way to track your life, including your blood. The simplest way to start is to create or adapt a spreadsheet that records a range of biomarker blood tests and provides a quick visualize check if your blood tests are in or out of your target range. You’ll want to then enter in your own results from your recent blood tests. Additionally for certain blood tests it makes sense to plot your changes over time.

Biomarker Tracker: While spreadsheets work, blood test tracking still feels like an area that merits dedicated mobile and web apps. In view of the lack of this type of app and need, I’m currently building a personal blood testing and biomarker tracking app. Leveraging a robust and open source biomarker database, this application makes it possible to log and aggregate all of your past results, visualize your trends and spot sub-optimal areas. Combining machine learning and existing research, we can predict results on additional tests and recommend commonly effective interventions. If you are interested, join our mailing list at www.biomarkertracker.com to become one of the first users.

Conclusion: What Blood Tests Should I Get? The Short Answer

Ultimately my goal is to equip people with the knowledge to make informed healthy choices using biometric and blood testing data. Tracking your blood biomarker tests is a key part in helping you on this data-driven journey towards towards optimization in heath, energy and performance too.

Now that we have answers to many of the most common questions about our blood, we can get to the question I get asked most often: Which tests should I get?. Or to put it another way:

When it comes to blood testing with an emphasis on health and wellness, which tests should you have done? And why?

Since personally tracking my blood for several years and more recently writing and building tools in the blood biomarker space, I get asked this question by nearly everyone who cares about their health and wants to measure it. This is a big question and topic and merits its own full post. In this conclusion I want to try and sketch out an initial answer.

One of the biggest challenges to establishing a baseline of blood tests is that there are a lot of tests. There are potentially hundreds of tests you could potentially do to quantify any number of aspects of your biochemistry. If we just picked the common tests that start with the letter “C,” should you get a CPK, CK, CBC, Cr, CRP, CBL or Ca? Besides the confusion of new terms and even reading your results, these lab tests all come with their own language of abbreviations too.

By my estimate, there exist at least several thousand lab tests on different biomarkers, and biomarker discovery remains extremely popular topic for both research and publication. Even if you reduce this to the most referenced and common biomarkers in medicine, I came up with a list of over 100 so-called “common” biomarkers in use today.

If pushed to answer, the short answer is that basically everyone should regularly get tested for three blood panels: 1. the Complete Blood Count (CBC) with Differential, 2. Basic Metabolic Panel (BMP) and 3. Comprehensive Metabolic Panel (CMP).

CBC covers your blood cells and includes 14 biomarkers, while BMP tests lipid levels (fatty substances in your blood like cholesterol), electrolyte levels (minerals), kidney function, and blood sugar levels. BMP covers around 20 biomarkers and provide an understanding of your metabolic state and risk potential for several diseases like heart disease. Both CBC and BMP are standard tests, can be done nearly anywhere and are quite inexpensive (between 30 and 60 usd).

As an extension of the BMP, CMP includes several additional tests related to kidney function, liver function, diabetic and parathyroid status, and electrolyte and fluid balance. It’s a bit more expensive (50-100 usd), but due its more encompassing health check, this is the health check I recommend having done at least once a year.

Beyond these core blood panels and key blood tests of roughly 40 or so biomarkers, things get a bit trickier in terms of additional tests you could and should get. Not only is it a question of how significant and meaningful a biomarker might be and its benefit but also its costs too. For example, a single specific biomarkers like Vitamin D can cost 50 usd or more for a single test. Until some of these specific tests decrease in cost, they are best done more periodically.

I recommend checking on at least three biomarkers: Hemoglobin A1c, Vitamin D, 25-Hydroxy and Homocysteine. Hemoglobin A1c (as known as Glycated hemoglobin) identifies the three-month average of plasma glucose concentration, and it indicates if your blood sugar is increasing and is a key way to know your risk of diabetes. Along with the core panels, this is a test I recommend getting done whenever you get your blood tested.

It’s fairly well-established now the importance of Vitamin D. We can get it from the sun as well as some foods. Vitamin D levels are highly correlated with various diseases and mortality risk. What’s less well-talked about is the global deficiency of Vitamin D, even even places with plenty of sunshine. Getting your Vitamin D levels checked can help you know your health situation as well as know how well supplementation is working for you. If you’ve never checked it, then definitely get it done. But once you’ve figured out an intervention with supplements and/or regular exposure to sunlight, then it’s necessary to get it checked as often.

Homocysteine has become an important biomarker to track. Homocysteine is an amino acid. When proteins break down, elevated levels of amino acids like homocysteine may be found in the bloodstream. Unfortunately, when the metabolism to cysteine of methionine to cysteine is impaired, homocysteine levels increase in the body. Your blood vessels become like sand paper, increasing the risk of diseases like heart attack and stroke and can be an early indicator of blood clots and atherosclerosis. High homocysteine do not cause any symptoms, so in order to check it you need to do a blood test. Fortunately, there are some well-known interventions that can make an immediate impact on improving your homocysteine. For example, I was personally able to improve my homocysteine level through supplementation using bioavailable forms of Vitamins B6, B12 and Folic Acids.

If cost isn’t an issue or you are feeling particularly “off,” I recommend getting your hormones screened, including Estradiol, Progesterone, and Testosterone. Additionally, if you are a serious athlete or under a lot of life stress, it might be good to check indicators of inflammation like C-Reactive Protein, Cortisol, and Thyroid-Stimulating Hormone (TSH). Some other good biomarkers include DHEA-Sulfate, Estimated Glomerular Filtration Rate (eGFR), and Ferritin, Folate.

In summary, your blood is one of the key biological systems. It’s used to transport oxygen, nutrients, hormones, and waste around the body. As such, it provides a way to understand your body and its health using regular blood testing. Hopefully this post provided you with straightforward answers on what is blood testing and some of the most common questions, including some of the best blood tests you can use to get started.