Overview

A complete blood count (CBC) is a blood test used to evaluate your overall health and detect a wide range of disorders, including anemia, infection and leukemia.

A complete blood count test measures several components and features of your blood, including:

• Red blood cells, which carry oxygen
• White blood cells, which fight infection
• Hemoglobin, the oxygen-carrying protein in red blood cells
• Hematocrit, the proportion of red blood cells to the fluid component, or plasma, in your blood
• Platelets, which help with blood clotting

Abnormal increases or decreases in cell counts as revealed in a complete blood count may indicate that you have an underlying medical condition that calls for further evaluation.