The secret decoder ring for understanding your CBC lab test
Did you know that the Complete Blood Count (or CBC) test is the most commonly requested lab test, and it typically costs less than $35? Did you also know that from that one test, you can learn a lot about your vitamin status, your levels of inflammation, and even your organ functions?
I would bet these thoughts haven’t crossed your mind, and it has nothing to do with your intelligence or your level of health awareness. Unless you’ve been very involved in your own health for a while, you might never have even seen a CBC result form. You just heard back that ‘your labs are normal’ and you were satisfied that there was nothing going on.
If you did get a chance to look at your results, the details probably didn’t make much sense. It’s pretty easy to recognize whether a value is in range or out of range, according to the lab…but what do all those crazy acronyms mean?
Let’s take a peek at the Complete Blood Count, or CBC and see what the values can tell us.
RBC – Red Blood Cell Count is a measure of the number of red blood cells in the lab sample. The red blood cells contain hemoglobin, which carries oxygen from the lungs to the rest of the body. A low RBC count might mean that you have some nutrient deficiencies, you’re overhydrating, or potentially more serious conditions like anemia or cancer. High levels of RBCs might indicate sleep apnea or hypoxia, dehydration, or lung disease.
Hemoglobin – Hemoglobin is a protein in the red blood cells that actually carries oxygen. There are about 280 million molecules of hemoglobin in each red blood cell, and adults have about 1 ¾ pounds of hemoglobin in their body. A low level of hemoglobin might indicate anemia, nutrient deficiency, or bleeding. A high level might indicate dehydration, low blood oxygen from smoking, apnea, or lung disease, or some types of heart disease.
Hematocrit is the percentage of your blood is made up of red blood cells. This is a measurement of volume, so both the number and size of the red blood cells play into this measurement. Low hematocrit values could be because you have a low RBC or because you have a low MCV (mean corpuscular volume). With a high hematocrit, you might have very large red blood cells, or a lot of them (or both).
MCV, or mean corpuscular volume, is a measure of the average size of your red blood cells. It is often calculated by taking the RBC value and the hematocrit to calculate the average size of the cells. Smaller cells are less capable of distributing oxygen because they have less hemoglobin Overly large cells contain only as much hemoglobin as a normal sized cell, but since there are fewer of them, the oxygen delivery is impaired. Red blood cells are largest when they are first produced, and decrease in size as the cells age so a high MCV would indicate a large number of young cells and a low MCV would indicate a large number of older cells.
MCH or MCHC is the mean corpuscular hemoglobin (concentration). This is the average weight of the hemoglobin in each red blood cell. These values are not particularly interesting on their own, but are useful in diagnosing the different types of anemias. Did you know there are 400 different kinds of anemia?
RDW is the red cell distribution width and it is a measure of how much variation there is in the size of your red blood cells. This is a key indicator of many early nutrient deficiencies, like B12, iron, and folate (B9). Remember that red blood cells start out larger and decrease in size over time. The ideal RDW is a mid-range value. Blood that has a higher RDW tells you that blood cells are being produced rapidly, perhaps in response to bleeding or to a low oxygen concentration. Blood with a lower RDW indicates that cells are not being produced fast enough, perhaps because of a nutrient deficiency, a bone marrow disorder, or other condition.
WBC is the number of white blood cells in the blood. Like the RBC measurement, the WBC measurement is a simple count. White blood cells are an indicator of immune function. More WBCs indicate a higher immune response, while a lower WBC might indicate some types of autoimmune disease, severe infections, and interference from medications like antibiotics or chemotherapy. Inside the WBC section, you’ll see details for lymphocytes, neutrophils, basophils, monocytes, and eosinophils. These subcategories of white blood cells help your practitioner better understand the kind of immune response that’s happening in the body.
There’s some other tests that sometimes show up on a CBC report, but these are the key measurements. You can see just how valuable the CBC test is in understanding how your body is functioning. There’s a lot of information here, and a trained holistic health pro can help you determine what steps to take next to bring your test values into the ideal range.
Your blood renews itself every 120 days, so you can use the CBC as a great indicator of your health status as you update and adapt your habits to a healthier lifestyle.
The next step to expert lab interpretation is to understand the ideal ranges for each of these key indicator tests. Go get my free Insider’s Guide to Lab Test Results so you can understand how your results stack up against the ideal values.