Complete Blood Count with Differential (CBC with Differential)

What Does Each Blood Cell Type Represent?

Your white blood cells (WBCs) are part of your immune system. A CBC with differential helps identify which types of WBCs are present, such as neutrophils (which fight infections), lymphocytes (which help with long-term immunity), monocytes (which clean up debris), eosinophils (which respond to allergies or parasites), and basophils (which release chemicals during allergic reactions). Abnormal counts can signal infections, inflammation, or immune system issues.

Red Blood Cells and Hemoglobin

Red blood cells (RBCs) carry oxygen to your body’s tissues. A CBC measures their number, size, and shape, as well as hemoglobin (the protein that binds oxygen). Low RBC counts or hemoglobin levels may indicate anemia, while unusual RBC shapes could suggest conditions like sickle cell disease or other blood disorders.

Platelets: Clotting and Bleeding Risks

Platelets are small cells that help your blood clot. A CBC counts them to check for bleeding disorders or excessive clotting. Low platelet counts can increase bleeding risk, while high counts may raise the risk of clots.

Why Might This Test Be Ordered?

Doctors order a CBC with differential for routine check-ups, to diagnose infections (like pneumonia or urinary tract infections), evaluate anemia, monitor chronic conditions (such as kidney disease or cancer), or check for signs of blood disorders or immune system problems.