What does a complete blood count (CBC) measure?

A complete blood count (CBC) is a comprehensive blood test that assesses multiple components of blood, making it a crucial tool in diagnosing and monitoring various health conditions. It measures the levels of white blood cells (WBCs), which are vital for immune function; red blood cells (RBCs), which carry oxygen throughout the body; hemoglobin, the protein in red blood cells that binds oxygen; hematocrit, which indicates the proportion of blood volume occupied by red blood cells; and platelets, essential for blood clotting.

By analyzing these components, healthcare professionals can gain valuable insights into a patient’s overall health, identify conditions such as anemia, infection, and other disorders, and evaluate the body's response to treatments. This multifaceted approach distinguishes the CBC from tests that only evaluate a single component of blood, such as glucose levels or coagulation factors, thus making it an essential diagnostic tool in clinical practice.