Background: Headache disorders are currently the sixth leading cause of disability across the globe and therefore carry a significant disease burden. This systematic review and meta-analysis aims to investigate the effects of yoga on headache disorders.

Methods: MEDLINE/PubMed, Scopus, the Cochrane Library, and PsycINFO were screened through May 2019. Randomized controlled trials (RCTs) were included when they assessed the effects of yoga in patients with a diagnosis of chronic or episodic headache (tension-type headache and/or migraine). Usual care (no specific treatment) or any active treatments were acceptable as control interventions. Primary outcome measures were headache frequency, headache duration, and pain intensity. For each outcome, standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated.

Results: Meta-analysis revealed a statistically significant overall effect in favor of yoga for headache frequency (5 RCTs; standardized mean difference (SMD) = - 1.97; 95% confidence interval (CI) - 2.75 to - 1.20; I² = 63.0%, τ² = 0.25, P = 0.03), headache duration (4 RCTs; SMD = - 1.45; 95% CI - 2.54 to - 0.37; I² = 69.0%, τ² = 0.33, P = 0.02), and pain intensity (5 RCTs; SMD = - 3.43; 95% CI - 6.08 to - 0.70, I² = 95.0%, τ² = 4.25, P < 0.01). The significant overall effect was mainly due to patients with tension-type headaches. For patients with migraine, no statistically significant effect was observed.

Discussion: Despite discussed limitations, this review found preliminary evidence of short-term efficacy of yoga in improving headache frequency, headache duration, and pain intensity in patients suffering from tension-type headaches. Further studies are urgently needed to draw deeper conclusions from the available results.