BETA - What is CBC Testing?

CBC stands for the complete blood count, which is a measurement of all of the types of blood cells that are circulating in our blood. CBC is a complete blood count. The most common indication outside cancer is to see whether people are anemic. People can be anemic because they have iron deficiency, because they have vitamin B12 deficiency, they have folate deficiency, or because of other reasons. But when you know that somebody is anemic, the next thing you want to know is are they only anemic or are the other counts like the platelet count and the white blood cell count also lower? And if they are also lower, then you know you're not simply dealing with an iron deficiency. There is much more going on than that. And that will require a bone marrow to find out what's going on. The most common reason to do a CBC in general practice is to see whether people are anemic, especially females. The CBC reflects the bone marrow function. And the bone marrow makes three different types of cells. It makes the red blood cells, it makes the white blood cells, and it makes the platelets. And the red blood cells are the cells that are carrying around oxygen and make us feel not tired. If we have a low red blood cell count, people will feel tired. The white blood cell count is related to infection. If the white blood cell count is low, there is an increased risk of infection. And the platelets are related to bleeding. If the platelet count is very low, there is an increased risk of bleeding. A CBC is performed by taking a small amount of blood in a special kind of tube to be analyzed for the different types of cells in your blood. CBCs are a really important part both of the diagnosis of multiple myeloma and other blood conditions, as well as monitoring effects of treatment, as well as side effects of treatment. So they're taken quite regularly, sometimes even weekly, but usually at least once a month in the course of treatment. I do recommend to all my patients to try to get at least their myeloma labs checked at the same lab over time, because there are subtle variations from lab to lab. When you're trying to make cross comparisons and looking at small numerical differences, it often creates more anxiety than any real difference in those labs. So we really try to encourage patients to use the same lab to get those drawn. It doesn't necessarily have to be the lab at the academic center, but the same lab is most important. It's especially important when there are minor changes. If there are major changes, every lab will find out that there's a major change. But if it's a minor change, then we have to know whether this is because we have a different lab or because there's really something brewing and going up. The only way to know that there is really a real increase is by using the same lab all the time. Otherwise, you have no idea whether this is due to differences in lab or whether there's really something going on with your myeloma. So one of the questions that often comes about is, I had my therapy, oftentimes a transplant, and my labs are still not normal. And that's not uncommon for labs to remain slightly lower than normal. It can be the hemoglobin and hematocrit. It can be the white blood cell count. It can be the platelet count, any or all of them. And usually that's because of effects on the bone marrow stem cells from the chemotherapy that has been given in the context of the transplant or collecting the cells or even prior to that. While somewhat disturbing to have a CBC report that doesn't all fall within the normal range, it is usually not clinically concerning to us because most patients have sufficient cells to support all that they need, even if they aren't entirely within the normal range. I would say with regard to your CBCs or any of your labs, if you have a question, ask. That's the most important thing. We want to make sure that everyone's educated and is able to interpret these things, but oftentimes a discussion is really important in looking at the laboratory values that are there.