CBC

Complete Blood Count (CBC)

The Complete Blood Count (CBC) is a fundamental blood test that is frequently ordered to assess a patient's overall health and detect a variety of disorders, including anemia, infection, and many other diseases. It is a comprehensive test that evaluates the cells that circulate in the blood, including red blood cells, white blood cells, and platelets.

Components of CBC

A CBC test typically includes the following components:

Red Blood Cell (RBC) Count

The RBC count measures the number of red blood cells in a given volume of blood. Red blood cells are responsible for carrying oxygen from the lungs to the rest of the body and returning carbon dioxide from the body to the lungs for exhalation.

• Hemoglobin (Hgb): This is the protein in red blood cells that carries oxygen. Low levels can indicate anemia.
• Hematocrit (Hct): This measures the proportion of blood volume that is occupied by red blood cells. It is expressed as a percentage.
• Mean Corpuscular Volume (MCV): This measures the average size of red blood cells. It helps in classifying anemias as microcytic, normocytic, or macrocytic.

White Blood Cell (WBC) Count

The WBC count measures the number of white blood cells in a given volume of blood. White blood cells are crucial for the immune system, helping to fight infections.

• Differential Count: This provides the percentages of different types of white blood cells, such as neutrophils, lymphocytes, monocytes, eosinophils, and basophils.

Platelet Count

Platelets are small cell fragments that are essential for blood clotting. The platelet count measures the number of platelets in a given volume of blood.

Indications for CBC

A CBC is often ordered as part of a routine health examination. It can also be used to:

• Diagnose conditions such as anemia, infection, and many other disorders.
• Monitor a medical condition and its treatment, such as the effects of chemotherapy.
• Monitor overall health.

Interpretation of Results

Interpreting CBC results requires understanding the normal ranges for each component, which can vary based on age, sex, and specific laboratory standards. Abnormal results may indicate:

• Anemia: Low RBC count, hemoglobin, or hematocrit.
• Infection or Inflammation: High WBC count.
• Bleeding Disorders: Low platelet count.

Limitations

While a CBC provides valuable information, it is not diagnostic on its own. Abnormal results often require further testing and clinical correlation to determine the underlying cause.

See Also

• Anemia
• Leukocytosis
• Thrombocytopenia

References

• "Complete Blood Count (CBC)." Mayo Clinic, [1].
• "Understanding Your Complete Blood Count (CBC)." American Society of Hematology, [2].