H and H (Hemoglobin and Hematocrit)

Blood is made up of red blood cells (RBC), white blood cells (WBC), and platelets which are suspended in a liquid called plasma. A hematocrit (HCT) lab test determines the percentage of the blood that is composed of RBC.

An HCT test helps your medical provider screen for, diagnose, and monitor conditions that affect your blood or bone marrow. A measurement of HCT is routinely included in a complete blood count (CBC) but may also be ordered on its own if your provider suspects a condition affecting your RBC.