The CBC medical abbreviation stands for complete blood count, a blood test requested more often than almost any other. It counts and measures the three main kinds of blood cells: red cells that carry oxygen, white cells that fight infection, and platelets that help blood clot.
A CBC is part of routine checkups, admission labs, pre-surgery testing and monitoring during treatments such as chemotherapy. You will see it in orders, nursing notes and portal results, sometimes as CBC with diff. Below you will find what each part measures, how to read a typical result, and the abbreviations that ride along with it, such as HCT and ANC.
At a glance
Stands for
Complete blood countMain parts
WBC, RBC, hemoglobin, hematocrit, platelets, red cell indicesWritten as
CBC, CBC w/ diff, CBC with differentialSample type
Blood, usually in a lavender or purple top tubeOutside the US
FBC, full blood count, in the UK and elsewhereDo not confuse with
Inside the CBC medical abbreviation
A complete blood count reports several numbers at once. The table lists the core values and rough adult ranges many labs use. Each lab prints its own range beside your result, and it can differ by age, sex and altitude.
| Value | What it measures | Typical adult range (approximate) |
|---|---|---|
| WBC | White blood cells | About 4,500 to 11,000 per microliter |
| RBC | Red blood cells | Varies by sex |
| Hgb | Hemoglobin, the oxygen carrying protein | About 12 to 15.5 g/dL in women, 13.5 to 17.5 in men |
| Hct | Hematocrit: what fraction of a spun sample is packed red cells | Roughly three times the Hgb value |
| Plt | Platelets | About 150,000 to 450,000 per microliter |
Red cell indices such as MCV (average red cell size) and RDW (variation in size) help sort out types of anemia.
What CBC with diff adds
The differential, or diff, splits the white cells into five types: neutrophils, lymphocytes, monocytes, eosinophils and basophils. Each type rises or falls for different reasons. Neutrophils often climb with bacterial infection, lymphocytes with many viral illnesses, and eosinophils with allergies or parasites.
From the diff, clinicians calculate the ANC, absolute neutrophil count, which matters a great deal during chemotherapy because a low ANC raises infection risk. Orders may read "CBC w/ diff" or "CBC with auto diff" when this breakdown is wanted.
Reading a CBC in a real note
In a morning note: "CBC: WBC 14.2, Hgb 9.1, Plt 210. Leukocytosis, likely reactive; anemia stable from yesterday." WBC 14.2 means 14,200 white cells per microliter, above the usual range. Hgb 9.1 is low, meaning anemia, but unchanged. Platelets are normal.
Many clinicians draw the CBC as a fishbone diagram: a cross shape with WBC on the left, hemoglobin on top, hematocrit below and platelets on the right. Students learn to read it quickly because it saves space in handwritten and typed notes.
Why a CBC is ordered
- Checking for anemia when someone is tired, pale or short of breath
- Looking for signs of infection or inflammation
- Watching blood counts during cancer treatment or with medicines that affect bone marrow
- Before surgery, to know the baseline and platelet count
- Tracking bleeding, for example after an injury or with a GI bleed
A CBC is a screening tool. An abnormal value usually leads to more questions and sometimes more tests, not to a diagnosis on its own.
CBC nursing abbreviation tips
For nurses and nursing students, the CBC is a daily companion. Common tasks include drawing or collecting the sample in the correct tube, flagging critical values, and connecting results to orders. Transfusion orders often refer to a hemoglobin threshold. Bleeding precautions may start when platelets drop. Neutropenic precautions follow a low ANC.
Handoff often sounds like "H and H stable", which means hemoglobin and hematocrit have not changed. The CBC is often drawn with chemistry panels such as the BMP; see more on the labs and tests hub.
CBC compared with chemistry panels
People often mix up the CBC with metabolic panels because they are drawn together. The CBC counts cells. A BMP or CMP measures dissolved chemicals such as sodium, potassium, glucose and kidney markers. Different tubes, different machines, different questions.
Small shifts outside a printed range are common and often harmless. Your doctor or nurse is the best person to explain your blood count in light of your health and medicines.
Frequently asked questions
What does CBC stand for in a blood test?
CBC stands for complete blood count. It measures red blood cells, white blood cells, hemoglobin, hematocrit and platelets from one small blood sample.
What is the difference between CBC and CBC with diff?
A plain CBC gives the total white cell count. CBC with diff also breaks white cells into their five main types, which helps point toward infection, allergy or other causes.
Is fasting needed before a CBC?
Usually not. A CBC alone does not require fasting, but it is often drawn with tests that do, so check the instructions on your lab order.
What does H and H mean with a CBC?
H and H means hemoglobin and hematocrit, two values from the CBC that track red cells. Nurses use the phrase when watching for bleeding or anemia.
Is CBC the same as FBC?
Yes. FBC, full blood count, is what Britain and many Commonwealth countries call the same test.