The Differences Between Blood‐pressure Measurements Obtained Simultaneously on the Two Arms

Seventy per cent. of a group of normal young adult males showed a significant difference between blood‐pressure measurements made simultaneously on the two arms. The distribution of the magnitude of these differences is presented. The same proportion of significant differences was found in 40 of the subjects when retested. The correlation between the magnitude of the differences for each individual in the two tests was low, indicating that the cause of the difference in blood‐pressure can rarely be a fixed structural characteristic of the individual. Since these differences are not easily reproducible by variation of standard physiological conditions, it is suggested that they may be of psychogenic origin.