Complete blood count (CBC)

A complete blood count (CBC) is a blood test. It's used to look at overall health and find a wide range of conditions, including anemia, infection and leukemia.

A complete blood count test measures the following:

• Red blood cells, which carry oxygen
• White blood cells, which fight infection
• Hemoglobin, the oxygen-carrying protein in red blood cells
• Hematocrit, the amount of red blood cells in the blood
• Platelets, which help blood to clot

A complete blood count can show unusual increases or decreases in cell counts. Those changes might point to a medical condition that calls for more testing.