The best time to take a blood sample from a patient with suspected reactive hypoglycaemia is during the spontaneous symptomatic episodes that occur in the patient's natural environment.
The patient, their spouse or another near relative can be taught how to collect capillary blood from a fingerprick onto specially prepared filter paper. If blood collected in this way shows a low glucose concentration on assay, the diagnosis of reactive hypoglycaemia can be seriously entertained.
