Inter-arm blood pressure differences in children could lead to wrong diagnosis Blood pressure measurements in children and adolescents should be taken from both arms after new research showed substantial differences could be seen depending on which arm was used. The study, led by the Murdoch Children's Research Institute (MCRI) and published in the Journal of Hypertension, found even a small difference in blood pressure measurements between arms could lead to a wrong diagnosis. MCRI PhD candidate and study lead author Melanie Clarke said this was the first study worldwide to determine the size and frequency of inter-arm blood pressure differences in children and adolescents.