Description: A CBC or Complete Blood Count with Differential and Platelets test is a blood test that measures many important features of your blood’s red and white blood cells and platelets. A Complete Blood Count can be used to evaluate your overall health and detect a wide variety of conditions such as infection, anemia, and leukemia. It also looks at other important aspects of your blood health such as hemoglobin, which carries oxygen.
Also Known As: CBC test, Complete Blood Count Test, Total Blood Count Test, CBC with Differential and Platelets test, Hemogram test
Collection Method: Blood Draw
Specimen Type: Whole Blood
Test Preparation: No preparation required
When is a Complete Blood Count test ordered?
The complete blood count (CBC) is an extremely common test. When people go to the doctor for a standard checkup or blood work, they often get a CBC. Suppose a person is healthy and their results are within normal ranges. In that case, they may not need another CBC unless their health condition changes, or their healthcare professional believes it is necessary.
When a person exhibits a variety of signs and symptoms that could be connected to blood cell abnormalities, a CBC may be done. A health practitioner may request a CBC to help diagnose and determine the severity of lethargy or weakness, as well as infection, inflammation, bruises, or bleeding.
When a person is diagnosed with a disease that affects blood cells, a CBC is frequently done regularly to keep track of their progress. Similarly, if someone is being treated for a blood condition, a CBC may be performed on a regular basis to see if the treatment is working.
Chemotherapy, for example, can influence the generation of cells in the bone marrow. Some drugs can lower WBC counts in the long run. To monitor various medication regimens, a CBC may be required on a regular basis.
What does a Complete Blood Count test check for?
The complete blood count (CBC) is a blood test that determines the number of cells in circulation. White blood cells (WBCs), red blood cells (RBCs), and platelets (PLTs) are three types of cells suspended in a fluid called plasma. They are largely created and matured in the bone marrow and are released into the bloodstream when needed under normal circumstances.
A CBC is mainly performed with an automated machine that measures a variety of factors, including the number of cells present in a person's blood sample. The findings of a CBC can reveal not only the quantity of different cell types but also the physical properties of some of the cells.
Significant differences in one or more blood cell populations may suggest the presence of one or more diseases. Other tests are frequently performed to assist in determining the reason for aberrant results. This frequently necessitates visual confirmation via a microscope examination of a blood smear. A skilled laboratory technician can assess the appearance and physical features of blood cells, such as size, shape, and color, and note any anomalies. Any extra information is taken note of and communicated to the healthcare provider. This information provides the health care provider with further information about the cause of abnormal CBC results.
The CBC focuses on three different types of cells:
WBCs (White Blood Cells)
The body uses five different types of WBCs, also known as leukocytes, to keep itself healthy and battle infections and other types of harm. The five different leukocytes are eosinophiles, lymphocytes, neutrophiles, basophils, and monocytes. They are found in relatively steady numbers in the blood. Depending on what is going on in the body, these values may momentarily rise or fall. An infection, for example, can cause the body to manufacture more neutrophils in order to combat bacterial infection. The amount of eosinophils in the body may increase as a result of allergies. A viral infection may cause an increase in lymphocyte production. Abnormal (immature or mature) white cells multiply fast in certain illness situations, such as leukemia, raising the WBC count.
RBCs (Red Blood Cells)
The bone marrow produces red blood cells, also known as erythrocytes, which are transferred into the bloodstream after maturing. Hemoglobin, a protein that distributes oxygen throughout the body, is found in these cells. Because RBCs have a 120-day lifespan, the bone marrow must constantly manufacture new RBCs to replace those that have aged and disintegrated or have been lost due to hemorrhage. A variety of diseases, including those that cause severe bleeding, can alter the creation of new RBCs and their longevity.
The CBC measures the number of RBCs and hemoglobin in the blood, as well as the proportion of RBCs in the blood (hematocrit), and if the RBC population appears to be normal. RBCs are generally homogeneous in size and shape, with only minor differences; however, considerable variances can arise in illnesses including vitamin B12 and folate inadequacy, iron deficiency, and a range of other ailments. Anemia occurs when the concentration of red blood cells and/or the amount of hemoglobin in the blood falls below normal, resulting in symptoms such as weariness and weakness. In a far smaller percentage of cases, there may be an excess of RBCs in the blood (erythrocytosis or polycythemia). This might obstruct the flow of blood through the tiny veins and arteries in extreme circumstances.
Platelets, also known as thrombocytes, are small cell fragments that aid in the regular clotting of blood. A person with insufficient platelets is more likely to experience excessive bleeding and bruises. Excess platelets can induce excessive clotting or excessive bleeding if the platelets are not operating properly. The platelet count and size are determined by the CBC.
Lab tests often ordered with a Complete Blood Count test:
- Iron and Total Iron Binding Capacity
- Basic Metabolic Panel
- Comprehensive Metabolic Panel
- Lipid Panel
- Vitamin B12 and Folate
- Prothrombin with INR and Partial Thromboplastin Times
- Sed Rate (ESR)
- C-Reactive Protein
- Epstein-Barr Virus
- Von Willebrand Factor Antigen
Conditions where a Complete Blood Count test is recommended:
- Aplastic Anemia
- Iron Deficiency Anemia
- Vitamin B12 and Folate Deficiency
- Sickle Cell Anemia
- Heart Disease
- Autoimmune Disorders
- Bleeding Disorders
- Epstein-Barr Virus
Commonly Asked Questions:
How does my health care provider use a Complete Blood Count test?
The complete blood count (CBC) is a common, comprehensive screening test used to measure a person's overall health status.
What do my Complete Blood Count results mean?
A low Red Blood Cell Count, also known as anemia, could be due many different causes such as chronic bleeding, a bone marrow disorder, and nutritional deficiency just to name a few. A high Red Blood Cell Count, also known as polycythemia, could be due to several conditions including lung disease, dehydration, and smoking. Both Hemoglobin and Hematocrit tend to reflect Red Blood Cell Count results, so if your Red Blood Cell Count is low, your Hematocrit and Hemoglobin will likely also be low. Results should be discussed with your health care provider who can provide interpretation of your results and determine the appropriate next steps or lab tests to further investigate your health.
What do my Differential results mean?
A low White Blood Cell count or low WBC count, also known as leukopenia, could be due to a number of different disorders including autoimmune issues, severe infection, and lymphoma. A high White Blood Cell count, or high WBC count, also known as leukocytosis, can also be due to many different disorders including infection, leukemia, and inflammation. Abnormal levels in your White Blood Cell Count will be reflected in one or more of your different white blood cells. Knowing which white blood cell types are affected will help your healthcare provider narrow down the issue. Results should be discussed with your health care provider who can provide interpretation of your results and determine the appropriate next steps or lab tests to further investigate your health.
What do my Platelet results mean?
A low Platelet Count, also known as thrombocytopenia, could be due to a number of different disorders including autoimmune issues, viral infection, and leukemia. A high Platelet Count, also known as Thrombocytosis, can also be due to many different disorders including cancer, iron deficiency, and rheumatoid arthritis. Results should be discussed with your health care provider who can provide interpretation of your results and determine the appropriate next steps or lab tests to further investigate your health.
NOTE: Only measurable biomarkers will be reported. Certain biomarkers do not appear in healthy individuals.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.
Reflex Parameters for Manual Slide Review
||1.5 x 10^3
||30.0 x 10^3
||100 x 10^3
||800 x 10^3
||8.00 x 10^6
|Relative Neutrophil %
||1% or ABNC <500
|Relative Lymphocyte %
|Relative Monocyte %
||<75 with no flags,
>100 and <130 with platelet clump flag present,
||Variant lymphs, blasts,
immature neutrophils, nRBC’s, abnormal platelets,
giant platelets, potential interference
|The automated differential averages 6000+ cells. If none of the above parameters are met, the results are released without manual review.
CBC Reflex Pathway
Step 1 - The slide review is performed by qualified Laboratory staff and includes:
- Confirmation of differential percentages
- WBC and platelet estimates, when needed
- Full review of RBC morphology
- Comments for toxic changes, RBC inclusions, abnormal lymphs, and other
- significant findings
- If the differential percentages agree with the automated counts and no abnormal cells are seen, the automated differential is reported with appropriate comments
Step 2 - The slide review is performed by qualified Laboratory staff and includes: If any of the following are seen on the slide review, Laboratory staff will perform a manual differential:
- Immature, abnormal, or toxic cells
- Disagreement with automated differential
- Atypical/abnormal RBC morphology
- Any RBC inclusions
Step 3 - If any of the following are seen on the manual differential, a Pathologist will review the slide:
- WBC<1,500 with abnormal cells noted
- Blasts/immature cells, hairy cell lymphs, or megakaryocytes
- New abnormal lymphocytes or monocytes
- Variant or atypical lymphs >15%
- Blood parasites
- RBC morphology with 3+ spherocytes, RBC inclusions, suspect Hgb-C,
- crystals, Pappenheimer bodies or bizarre morphology