Objective: This study was conducted to characterize the prevalence, temporal patterns, and the degree of vomiting-induced migraine pain relief (VIMPR).
Background: Although data in the literature and anecdotal patient reports indicate the occurrence of VIMPR, its detailed characterization remains unstudied. Knowledge gaps are present regarding the extent and the temporal dynamics of pain relief upon vomiting in patients with migraine.
Methods: We conducted an explorative, cross-sectional, questionnaire-based study on patients with migraine referring at the Headache Center of Careggi University Hospital, Florence, Italy (June-December 2023). We assessed vomiting frequency, number of episodes, pain intensity (numerical rating scale [0-10]) for attacks with and without vomiting, temporal relationship between vomiting and VIMPR, pain recurrence patterns, as well as vomiting induction behaviors.
Results: Among 106 patients with migraine, 82 of 106 (77.4%; 95% confidence interval [CI], 68.5%-84.3%) reported vomiting during attacks. Attacks with vomiting were significantly more painful than those without (median, 9.0 vs. 7.0, Wilcoxon signed-rank test, V = 70, p < 0.001, r = 0.77). VIMPR occurred in 45 of 82 patients (54.9%; 95% CI, 44.1%-65.2%), with 12 of 82 (14.6%) experiencing complete attack cessation whereas 33 of 82 (40.2%) only temporary reduction. Of the 45 patients experiencing VIMPR, onset of pain relief occurred within seconds in 13 of 45 (28.9%), within minutes in 18 of 45 (40.0%), and within hours in 14 of 45 (31.1%). For those with pain recurrence, 57.6% experienced reduced intensity compared to pre-vomiting levels. Voluntary vomiting induction was reported by 22 of 82 patients (26.8%; 95% CI, 18.4%-37.3%) and was more common among those who had experienced VIMPR (18 of 45, 40.0%) compared to those without VIMPR (4 of 37, 10.8%; χ2(1) = 7.39, p = 0.007).
Conclusions: Vomiting seems to provide pain relief and/or pain freedom in more than half of patients with migraine. Although the cross-sectional, self-reported nature of our data does not allow definitive conclusions regarding underlying mechanisms, the rapid onset of VIMPR reported by patients and the learned behavior of voluntary vomiting induction are consistent with the involvement of endogenous antinociceptive pathways. Future studies employing neuroimaging techniques, prospective designs, along with the consistent documentation of acute medication use, are needed to elucidate whether VIMPR represents a genuine endogenous neurobiological mechanism and to characterize the potential underlying pathways.
Keywords: endogenous analgesia; migraine; self‐medication behavior; vomiting‐induced pain relief.
Vomiting during a migraine is often seen as a debilitating symptom, but in our questionnaire‐based study, we found that more than half of people with migraine who vomit during an attack experience meaningful pain relief afterward, and for some, pain disappears within minutes. Some people reported intentionally inducing vomiting as a way to manage their migraine attacks. Better understanding why and how vomiting can cut a migraine attack short could offer important clues about the underlying mechanisms of migraine.
© 2026 The Author(s). Headache: The Journal of Head and Face Pain published by Wiley Periodicals LLC on behalf of American Headache Society.