What You Need to Know About Lab Tests

"My doctor said my labs were normal so there is nothing wrong with me. But I still feel bad." I hear some variation of this statement all the time. This tells me that as doctors and as patients, we fundamentally don't understand laboratory tests and how to use them. Here is what you need to know about lab tests to be a savvy patient:

Understanding Reference Ranges

Reference ranges are the values by which we determine if your results are normal or not normal. But what do the reference ranges mean? How are they determined? Reference ranges are determined by testing "healthy" individuals and seeing what values they get. Through statistical analysis, they get rid of outliers and define the normal range.

While this approach makes sense, there are a few issues. First, there are often slight discrepancies in reference ranges depending on the laboratory company. So for one company, you may fall in the normal reference range, but if you ran the test with a different company, they may tell you that you're high or low. 

The biggest problem, though, is with this "healthy" population that defines the reference range. Are they really healthy? Or are they just not sick? Because there is a big difference between the two. Being "not sick" simply means that you don't have signs and symptoms of disease. It does not mean that your cellular health is excellent, that you have strength and stamina, that your body is functioning optimally. So when these people who are not truly healthy are used to define reference ranges, we get broader reference ranges that include values that are less than optimal, that may indicate a trend towards disease.

That is why many practitioners ignore the standard reference range and use a functional reference range. This range is often narrower and is used to determine optimal values for true health and wellbeing and is also used to prevent disease.

An example of using a functional reference range instead of a standard reference range is TSH. TSH is thyroid stimulating hormone and it is the first test doctors order if they think there is a problem with your thyroid. The standard range for TSH is 0.45 to 5.5 while the functional range is 1.8 to 2.5. So if your TSH is 4, your doctor may tell you that your thyroid is normal. But when using the functional range, we know that you are trending towards hypothyroidism if you're aren't already there. Using the standard range, your doctor may not do anything for you and let you get sicker. Using the functional range, your doctor would take action to help you get better now instead of waiting. 

Evaluating Pathology Vs. Physiology

What does it mean when your lab values are above the standard reference range? For most blood tests, having high values means that you are right in the middle of a disease process. This is called pathology. Your cells are dying and spilling their contents into the blood and your organs are not functioning well.

The abnormal lab values tell us that there is disease, but not necessarily what disease or how and why that disease happened. 

When we focus on identifying abnormal lab values, we are focusing on pathology. And while pathology is important, when you want to figure out the real cause of disease, physiology is much more important. That is why naturopathic/functional medicine doctors often order more labs and labs that go beyond basic blood tests (such as hormones, genetics, nutrients, neurotransmitters, gut bacteria, etc). We are not necessarily hunting for abnormal lab values but we are trying to understand your physiology. We are trying to understand what is happening in your body and in your cells so we can pinpoint the real problem and treat that. 

Not Treating Lab Values

Another pitfall that many practitioners fall into is treating lab values. For example, if you have high cholesterol on a basic lipid panel, your doctor may recommend that you take a statin or possibly a more natural pill like niacin or red yeast rice. But they are treating your lab value, not you, not your physiology and not your health. Instead of treating your lab value, your doctor should be asking why. Why is your cholesterol high? Is it a hereditary problem? Or is it due to a dietary issue? Is your high cholesterol really a problem? Do you have inflammation or high blood sugar? Is your cholesterol being oxidized? Do you have active cholesterol build up in your blood vessels? (And yes, there are tests to evaluate inflammation, oxidization, and potential plaques.) A doctor who approaches your abnormal lab value from this perspective is focused on understanding the meaning of the lab in terms of your unique physiology and creating a customized treatment plan that will be more effective and actually cultivate health. 

So the next time you visit your doctor, pay attention to how they approach lab tests. Do they resist ordering a test if you aren't already sick? Do they order the bare minimum of tests? Do they explain the meaning of the lab tests (even the ones that are within the normal range)? Do they tell you that your labs are normal so you're fine? 

If so, it might be time for a new doctor. When you're interviewing new doctors, ask them about their approach to laboratory testing. Do they use a functional reference range or just the standard reference range? Do they just use basic blood work or do they use specialized tests? 


I'm Dr. Carly and my mission is to create a health revolution. I believe that another prescription is not the answer. I believe in using natural therapies that go beyond the symptoms. And I believe that doctors should spend way more than 7 minutes with a patient.