Hematocrit ( HCT )

Also known as : Hematocrit ; Crit ; Packed cell volume ; PCV ; H and H ( Hemoglobin and Hematocrit ) . 
Formal name : Hematocrit .
Related tests : Complete Blood Count , Hemoglobin , RBC Count , Blood Smear , Iron Tests , Reticulocyte Count , Vitamin B12 and Folate , Red Cell Indices , Bone Marrow Aspiration and Biopsy , G6PD , Erythropoietin , Hemoglobin Variants .

Why should I do it ?
To determine the proportion of your blood that is made up of red blood cells ( RBCs ) , thus to screen for , help diagnose , or monitor conditions that affect RBCs ; as part of a routine health examination or if your doctor suspects that you have anemia or polycythemia . 

When should I do it ?
With a test for hemoglobin or as part of a complete blood count ( CBC ) during a routine health exam or when your doctor suspects you have a condition such as anemia ( low hematocrit ) or polycythemia ( high hematocrit ) ; at regular intervals to monitor a disorder that affects RBCs and to evaluate treatment effectiveness . 

What Kind of Sample is Needed ?
A blood sample drawn from a vein in your arm or by a fingerstick ( children and adults ) or heelstick ( newborns ) . 

Test Preparation Needed ?
None .