Complete blood count (CBC)

Definition

A complete blood count (CBC) is a comprehensive blood test that evaluates various components of the blood, including red blood cells, white blood cells, hemoglobin, hematocrit, and platelets. This test provides critical insights into a person's overall health and is especially useful in diagnosing conditions like anemia and polycythemia, where the balance of these components is disrupted.

5 Must Know Facts For Your Next Test

1. The CBC provides key metrics such as red blood cell count, white blood cell count, hemoglobin concentration, hematocrit percentage, and platelet count.
2. Abnormal CBC results can indicate a range of health issues, from infections and inflammation to more serious conditions like leukemia or bone marrow disorders.
3. In anemia, CBC results typically show low hemoglobin levels and may indicate changes in red blood cell size or shape.
4. For polycythemia, the CBC will show elevated red blood cell counts and increased hemoglobin levels, which can raise the risk for thrombotic events.
5. The CBC is often part of routine health assessments and preoperative evaluations, making it a vital tool for early detection of potential health problems.

Review Questions

• How does a complete blood count assist in diagnosing anemia?
  • A complete blood count assists in diagnosing anemia by measuring levels of hemoglobin and hematocrit along with the red blood cell count. Low levels of hemoglobin indicate a reduced capacity for oxygen transport, while a low hematocrit percentage reveals less volume of red blood cells in circulation. Changes in red blood cell size or shape may also be observed in the CBC results, which further aid in determining the specific type of anemia present.
• Discuss the implications of elevated red blood cell counts observed in a complete blood count for patient management.
  • Elevated red blood cell counts observed in a complete blood count can indicate polycythemia, which increases the risk of complications such as thrombosis and hypertension. In managing patients with this condition, healthcare providers may consider interventions like phlebotomy to reduce red blood cell mass or medications to address underlying causes. Close monitoring through repeat CBCs is essential to assess treatment effectiveness and prevent potential complications associated with increased blood viscosity.
• Evaluate the significance of integrating complete blood count results with other clinical data when assessing a patient’s overall health status.
  • Integrating complete blood count results with other clinical data is crucial for a comprehensive assessment of a patient's health status. For instance, combining CBC results with patient history, physical examination findings, and other laboratory tests helps clinicians identify patterns that may signify underlying conditions. This holistic approach enables more accurate diagnosis and tailored treatment plans, as it allows for the consideration of factors such as nutritional deficiencies, chronic diseases, or acute infections that could influence the CBC findings.

Related terms

Anemia: A condition characterized by a deficiency of red blood cells or hemoglobin in the blood, leading to reduced oxygen transport in the body.

Polycythemia: A disorder that results in an increased number of red blood cells in the bloodstream, which can lead to increased blood viscosity and other complications.

Leukocytes: White blood cells that are part of the immune system, helping the body to fight infections and other diseases.