Table of ContentsView AllTable of ContentsHow a CBC Is DoneAbnormal ValuesRed Blood Cell Count (RBCs)White Blood Cell Count (WBCs)HematocritHemoglobinPlatelet Count (Thrombocytes)
Table of ContentsView All
View All
Table of Contents
How a CBC Is Done
Abnormal Values
Red Blood Cell Count (RBCs)
White Blood Cell Count (WBCs)
Hematocrit
Hemoglobin
Platelet Count (Thrombocytes)
A CBC, also known as a complete blood count, is ablood testcommonly performed before and after surgery. This test measures the types of blood cells in your blood and how many appear, allowing your provider to see if your blood is normal or if there are signs of a problem.
The CBC is very useful because it can indicate many common problems in patients during surgery and their recovery. For this reason, a CBC may be drawn before surgery to “establish a baseline” for comparison with labs drawn after surgery.
This way, it will be more obvious if there is a large change after surgery or if something very serious, like bleeding, happens during the hours and days after surgery. This test may revealsigns of infection, dehydration,anemia, the need for a post-surgery transfusion, and even chronic conditions, such asblood cancers.
While these tests are often done before and after surgery, they are also frequently done as part of a routine physical when there is no apparent health problem. This is considered screening and is done to catch problems in the early stages before they become serious.
A CBC is one of the most common blood tests done in health care and is almost always a part of routine blood work.
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Blood can be drawn from a vein, or if you have a special IV inserted for surgery, it may be drawn from that line. Blood is typically drawn from a blood vessel directly into a special type of test tube that prevents it from clotting. It is then sent to a lab for processing.
Keep in mind that “normal” values can vary slightly based on simple changes such as the elevation at which you live. Other factors which can affect values are hydration status and use of certain medications. Different labs also have slight differences in the “normal ranges.”
The information and potential diagnosis listed for high and low levels in the following paragraphs is just a list of possible causes—it doesn’t mean you have any of these problems. Do not assume anything about your blood tests without speaking to your provider as interpreting the results is both an art and a science and this article cannot replace the extensive education that providers receive.
Red blood cellscarry oxygen to the body.
Normal Values:Men: 4.7 to 6.1 million cells per microliter.Women: 4.2 to 5.4 million cells per microliter
Normal Values:
Low results can indicate blood loss, problems with the bone marrow, leukemia, and malnutrition. High results can indicate heart problems, kidney disease, over transfusion and dehydration.
These cellsare the infection-fighting portion of the blood and play a role in inflammation.
Normal Values: 4,500 to 10,000 cells/mcl
A low count can indicate bone marrow problems or other issues preventing the body from making enough of these blood cells, chemical exposure, autoimmune disease, and problems with the liver or spleen.
High levels can indicate the presence of tissue damage (burns), leukemia and infectious diseases, or the use of certain medications such as steroids.In addition, inflammation after surgery may cause a slightly elevated white blood cell count.
This isthe percentage of the bloodthat is composed of red blood cells.
Normal Values:Men: 40.7% to 50.3%Women: 36.1% to 44.3%
Lowhematocrit levelscan indicate anemia, blood loss, bone marrow problems, malnutrition and more. High levels can indicate dehydration, polycythemia vera, smoking, living at a high altitude and heart diseases that are present at birth.
Hemoglobinis a protein on red blood cells that carries oxygen. Too few red blood cells is called anemia.
Normal Values:Men: 13.8 to 17.2 grams/deciliterWomen: 12.1 to 15.1 grams/deciliter.
Platelets are the part of the blood that makes the blood clot.
Normal Values: 150,000 to 400,000 per mm3.
Low levels may indicate the person is receiving chemotherapy, hemolytic anemia, the presence of a replacementheart valve, leukemia, or a recent blood transfusion. Low levels after surgery may be reflective of a “consumptive” coagulopathy, where platelets are used during the clotting and recovery process.
Another cause may be heparin-induced thrombocytopenia, where heparin (a commonly used blood thinner in hospitals) may cause low levels of platelets, either from a direct or autoimmune effect on the platelets.
A Word From Verywell
The CBC is a very useful test, but not as easy to interpret as you may believe, as there are many things to take into account when determining if there is a problem and what should be done about it. For example, a lower hemoglobin after surgery than before may indicate blood loss, but it takes a full understanding of the procedure that was done to know how much blood loss likely occurred during surgery, and if the changes on the labs indicate a major problem or a routine recovery.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Testing.com.CBC blood test (complete blood count).Testing.com.Red blood cell count (RBC) test.Tedting.com.Hematocrit blood test.Testing.com.Hemoglobin blood test.Testing.com.Platelet count (PLT) blood test.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Testing.com.CBC blood test (complete blood count).Testing.com.Red blood cell count (RBC) test.Tedting.com.Hematocrit blood test.Testing.com.Hemoglobin blood test.Testing.com.Platelet count (PLT) blood test.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Testing.com.CBC blood test (complete blood count).Testing.com.Red blood cell count (RBC) test.Tedting.com.Hematocrit blood test.Testing.com.Hemoglobin blood test.Testing.com.Platelet count (PLT) blood test.
Testing.com.CBC blood test (complete blood count).
Testing.com.Red blood cell count (RBC) test.
Tedting.com.Hematocrit blood test.
Testing.com.Hemoglobin blood test.
Testing.com.Platelet count (PLT) blood test.
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