Complete Blood Count

Three key tests measure how well your red blood cells carry oxygen throughout the body, including:

Red Blood Cell Count (RBC)—measures the number of red blood cells (or erythrocytes) in your blood

Hematocrit (HCT)—measures the percentage of your blood volume filled by red cells (bigger cells, which can carry more oxygen, take up more room)

Hemoglobin (HGB)—measures the most important part of your red cells—the crucial oxygen-carrying hemoglobin molecule


Other measures include:
Platelets—measures the number of platelets (thrombocytes) needed for blood clotting. Blood may not clot properly if platelet counts are low.
 
White Blood Cell Count (WBC)—measures the total number of infection-fighting white cells or leukocytes

Test Tip: Low RBC, HCT or HGB values are a sign of anemia, which could mean less oxygen in your blood and less energy for you. Note: Women are more prone to anemia than men. Treatments vary, so talk with your doctor about what you can do to stay healthy.