Several studies suggest that patients with migraine respond physiologically to stress differently from controls, yet experimental data are scarce. In order to evaluate the reactivity to stress in migraine, we recorded the quantitative electroencephalogram (qEEG) during non-noxious and noxious ischaemic arm stress in two groups of healthy controls and compared the results with the effects of non-noxious ischaemic arm stress in a group of patients with migraine. In the controls, non-noxious mild stress did not produce any qEEG change but noxious stress induced a significant decrease of the alpha power. By contrast, in migraine patients the non-noxious mild stress was sufficient to induce a significant decrease of the alpha power in all brain regions. The results of our study show that migraine sufferers display a lower threshold to physical stress and confirm previous studies indicating that migraine is a disease characterized by a state of altered neuronal excitability.