This study examined the stress-headache relationship from a disregulation framework by monitoring both physiological responses (eg, pulse, blood volume, skin resistance, and EMG) and self-reported responses to a stressful event in tension and migraine headache sufferers, as well as in headache-free controls. Responses were analyzed via time-series analyses to determine whether self-reports of stress were correlated with physiological measures of stress. It was hypothesized that tension and migraine headache sufferers would show fewer significant correlations than control participants between their self-reports of stress and physiological activity. Data analyses supported this hypothesis for tension headache sufferers, but generally not for migraine headache sufferers. The most compelling support for the hypothesis in tension headache sufferers came from the cross-correlations between self-reported stress and pulse rate.