MCV
What it measures, and what changes the number.
MCV, mean corpuscular volume, is the average size of the red blood cells. Automated analyzers measure it directly as cells pass through a sensor, and it is one of the most used red cell indices.
It is read with MCH, MCHC and RDW to describe red cell size and variation, and with hemoglobin, hematocrit and the red cell count. When size is being looked into, it is often reviewed next to ferritin, vitamin B12 and folate, and sometimes reticulocytes.
The sample is drawn into an EDTA tube and fasting is not needed. Red cells swell slowly if blood sits at room temperature, so a long delay before analysis can raise the reading. Very high blood glucose and cold agglutinins can also affect the measurement. Labs may print it as Volum corpuscular mig (VCM) or Volumen corpuscular medio (VCM).
Often read alongside: MCH, MCHC, RDW, Hemoglobin, Red blood cells