RDW measures how much your red blood cells vary in size. This page explains what the analyzer is computing, why 15.9% is flagged high, how to read RDW alongside MCV and hemoglobin, and how to track it as a longitudinal signal in your own data.
MCHC is a computed ratio of hemoglobin to hematocrit, and most high values are analyzer artifacts rather than biology. How to tell the difference using your own CBC history, and the few red cell conditions that genuinely raise it.
Mean platelet volume is a derived number from a fitted histogram, and it drifts with tube age and analyzer model. Here is how to tell a real low MPV from a preanalytical artifact, and what to measure alongside it.