What is the term for the percentage of red blood cells (RBC) in a blood sample?

The term for the percentage of red blood cells in a blood sample is hematocrit. Hematocrit is a crucial measurement in evaluating blood composition, allowing healthcare providers to assess whether a person has a normal, elevated, or decreased red blood cell volume. This measurement is expressed as a percentage; for example, a hematocrit of 45% means that 45% of the total blood volume consists of red blood cells.

The assessment of hematocrit is vital for diagnosing various medical conditions, such as anemia, polycythemia, and other blood-related disorders. It helps indicate the blood's oxygen-carrying capacity, which is especially important in evaluating a person's overall health.

The other terms listed, such as plasma volume and serum fraction, refer to different components of blood. Plasma volume pertains to the liquid part of the blood where cells are suspended and does not specifically indicate red blood cells' proportion. Serum fraction relates to the part of blood that remains after coagulation and also does not represent the red cell portion. Red cell mass refers to the total amount of red cells in circulation but does not quantify it as a percentage of the overall blood volume. Hence, hematocrit is the most accurate term for the percentage of red blood