Spanou I, et al. - Researchers examined how primary headaches are related to hypothyroidism and to elucidate its pathophysiological basis via a literature review. Performing a systematic search in the MEDLINE database, they identified 640 articles; of these, 9 were included in this work. The included studies showed vast heterogeneity across concerning population, study design, and outcomes. Thereby suggesting the inadequacy of the existing data to answer with certainty the relationship between headaches and thyroid disorders. As per the analysis, headaches and especially migraine may have a bidirectional association with hypothyroidism.