Complete Blood Count (CBC)
A complete blood count (CBC) gives important information about the
kinds and numbers of cells in the blood, especially
red blood cells ,
white blood cells , and
platelets. A CBC helps your doctor check
any symptoms, such as weakness, fatigue, or bruising, you may have. A CBC also
helps him or her diagnose conditions, such as
anemia, infection, and many other disorders.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Normal values for the complete blood count (CBC) tests depend
on age, sex, how high above sea level you live, and the type of blood sample.
Your doctor may use all the CBC values to check for a condition.
For example, the red blood cell (RBC) count, hemoglobin (Hgb), and hematocrit
(HCT) are the most important values needed to tell whether a person has anemia,
but the red blood cell indices and the blood smear also help with the diagnosis
and may show a possible cause for the anemia.
To see if the white
blood cell (WBC, leukocyte) count is good and how the cells look on the smear,
your doctor will look at both the number (WBC count) and the WBC
differential. To see whether there are too many or too few of a certain type of
cell, your doctor will look at the total count and the percentage
of that particular cell. There are normal values for the total number of each
type of white cell.
Pregnancy can change these blood values. Your
doctor will talk with you about normal values during each
trimester of your pregnancy.
White blood cell (WBC, leukocyte) count
|Men and nonpregnant women:
5,000–10,000 WBCs per cubic millimeter (mm3) or 5.0–10.0 x
109 WBCs per liter (L)
White blood cell types (WBC differential)
| Band neutrophils:
Red blood cell (RBC) count
4.5–5.5 million RBCs per
microliter (mcL) or 4.5–5.5 x
4.0–5.0 million RBCs per mcL
or 4.0–5.0 x 1012/L
3.8–6.0 million RBCs per mcL
or 3.8–6.0 x 1012/L
4.1–6.1 million RBCs per mcL
or 4.1–6.1 x 1012/L