A basic blood count (BBC) differs from a complete blood count (CBC) in its scope: a BBC provides key blood parameters—red blood cell (RBC), white blood cell (WBC), platelet (PLT), hemoglobin, and hematocrit—while a complete blood count (CBC) provides a detailed RBC and platelet count, as well as a breakdown by WBC type. A complete blood count (CBC) is often referred to as a CBC with differential. Laboratory terminology can vary, so it's important to check the list of parameters when ordering the test and always discuss the results with your doctor.
To sum it up
- Main morphological features : red blood cells (RBC), white blood cells (WBC), platelets (PLT), hemoglobin (HGB) and hematocrit (HCT).
- Complete blood count – additionally red blood cell indices (MCV, MCH, MCHC, RDW), platelet indices (eg MPV, PDW) and usually a smear.
- Smear (in percent) shows the number of neutrophils, lymphocytes, monocytes, eosinophils and basophils.
- The smear may be automatic (analyzer) or microscopic – assessed manually by a diagnostic physician.
Basic morphological features – what do they include?
A complete blood count (CBC) is a test that measures the number and characteristics of blood cells: red blood cells, white blood cells, and platelets. Main results include:
- RBC – the number of red blood cells (erythrocytes).
- HGB – hemoglobin concentration,
- GKT – hematocrit, that is, the proportion of blood cells in the blood volume.
- WBC – the number of leukocytes (the number of white blood cells).
- PLT – platelet count (thrombocyte count).
This test provides a general overview—it can indicate, for example, anemia, infection, or platelet count abnormalities—but does not pinpoint a specific problem. The white blood cell count is reported as a total, without distinguishing between different types.
Complete blood count and blood test with microscopic examination of a smear.
Complete morphology includes the main parameters and indicators describing the appearance and structure of cells:
- Red blood cell counts : MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin mass), MCHC (mean corpuscular hemoglobin concentration), RDW (red blood cell size difference);
- Platelet counts : MPV (mean platelet volume), PDW (platelet size variability), sometimes PCT;
- Smear, i.e. differential formula of leukocytes : percentage and absolute number of neutrophils, lymphocytes, monocytes, eosinophils and basophils.
Red blood cell counts help the doctor determine the type of anemia (for example, whether the red blood cell count is lower or higher than normal). A smear shows which white blood cells are responsible for the change in count—one diagnosis is suggested by a predominance of neutrophils, another by a predominance of lymphocytes or eosinophils.
Automatic and microscopic smear
The smear can be prepared using hematology analyzer , which automatically counts and classifies cells—this is how most of the results are generated. Microscopic (manual) smear This involves examining a stained blood sample under a microscope. It allows for a more precise assessment of cell size and shape, as well as the detection of immature cells or abnormal inclusions, among other things. It is typically performed when an automatic result is abnormal, the analyzer reports atypical cells, or as directed by a physician.
How to read the names of laboratory tests?
In price lists and test referrals, you may come across different names for the same or similar tests: «complete blood count,» «peripheral blood test,» «complete blood count,» «complete blood count with differential leukocyte count,» «complete blood count with differential leukocyte count,» and in English-language descriptions, «complete blood count» ( complete blood count ). There is no single definition of the terms "complete blood count" or "complete blood count" that applies to all laboratories.
So, instead of relying solely on the name, check list of parameters In the test description. If it includes neutrophils, lymphocytes, monocytes, eosinophils, and basophils, then the test includes microscopic examination (smear). If your doctor specifically ordered microscopic (manual) examination, make sure the lab performs it, as it is not always part of the standard procedure.
Comparison table: basic and complete morphology
| Characteristic | Main morphological features | Complete blood count (with microscopic examination of a smear) |
|---|---|---|
| Red blood cells | red blood cells, hemoglobin, hematocrit | RBC, HGB, HCT + MCV, MCH, MCHC, RDW |
| White blood cells | Leukocytes - total number | Leukocytes + division into neutrophils, lymphocytes, monocytes, eosinophils, basophils |
| blood platelets | PLT | PLT + MPV, PDW (sometimes PCT) |
| Method | Automatic analyzer | Analyzer; microscopic smear if necessary. |
| Diagnostic value | General screening | This allows you to narrow down the range of possible causes of the malfunction. |
| Typical use | Examinations | Diagnosis of anemia, infections, blood diseases, treatment monitoring. |
| Preparation | Usually on an empty stomach, in the morning. | Usually on an empty stomach, in the morning. |
Which morphology should I choose and how should I prepare the sample?
For a healthy person, a complete blood count (CBC) is often sufficient for a preventative examination. It's worth checking the test description to see what parameters it includes—in many labs, a standard CBC already includes parameters for red blood cells and platelets. A doctor will usually prescribe OAC with differential White blood cell counts if the basic CBC shows abnormalities (especially in the white blood cell count), in cases of recurrent infections, if anemia, autoimmune or hematological diseases are suspected, or for monitoring treatment.
Preparation for both tests is the same. Blood is usually taken in the morning, on an empty stomach , 8-12 hours after your last meal, after a few minutes of rest. It is best to avoid intense physical activity and smoking before the test. Remember that normal ranges vary depending on the laboratory, age, and gender , and a single result slightly outside the normal range does not necessarily indicate a disease—interpretation of the results should be left to a physician. If the test is repeated, it is best to have it performed in the same laboratory at a similar time, which will facilitate comparison of results.
Frequently Asked Questions (FAQ)
Is a complete blood count the same as a blood smear test?
This is often the case—many labs use these terms interchangeably. However, some institutions refer to this as a "complete" blood count with all parameters but without a differential white blood cell count. Before ordering the test, check the description to see if it includes a differential white blood cell count.
What is a blood smear?
A white blood cell (WBC) differential count measures the percentage of each type of white blood cell: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. It can be performed by a blood analyzer or a diagnostic physician by examining a sample under a microscope.
Do I need to fast before a blood test?
It is recommended to collect blood in the morning on an empty stomach, 8-12 hours after your last meal. You can drink some water. If you are taking any medications, consult your doctor to determine whether they are appropriate before the test.
In what cases does a doctor prescribe a microscopic examination of a smear?
Most often, when an automatic result is abnormal, the analyzer detects abnormal cells or suspects a blood composition disorder. Microscopic examination allows for a more detailed study of the cell shape and size.
What should I do if my blood test result is abnormal?
Show the results to your doctor. Minor deviations may be caused by factors such as a previous infection or dehydration, but your doctor should assess whether further diagnostics or repeat testing are necessary.
See also
- What is the difference between scintigraphy and PET?
- What is the difference between a CT scanner and an MRI?
- What is the difference between hysteroscopy and curettage?
- What is the difference between an optical microscope and an electron microscope?