Although the mean corpuscular volume (MCV) has been associated with various dis-eases, these associations in relation to the age- related trends in MCV remain unclear. Therefore, we used a dataset with over one million values to identify the relationship between ageing and MCV changes. All laboratory data obtained between November 1998 and November 2019 at Chungbuk National University Hospital were retrospec-tively collected. After excluding cases with missing values for individual complete bloo ...