BackgroundLimited epidemiological data are available for headache disorders in Japan, and no recent studies have reported the impact of several primary headache disorders in Japan. This study aimed to report the up-to-date epidemiological data and impact of primary headaches on daily activities as well as the use of medical care, clinical features, and pain severity/activity impairment using nationwide data in Japan.MethodsWe used anonymized online survey data coupled with medical claims data, from individuals aged 19–74 years old, that were provided by DeSC Healthcare Inc. The outcomes included the prevalence of migraine, tension-type headache, cluster headache, and other headache types stratified by age and sex, use of medical care, clinical features, medication use, and severity of pain/activity impairment. All outcomes were examined separately for each headache type. This is the second paper reported concurrently with this research.ResultsThe study population comprised 691/1,441/21/5,208 individuals with migraine/tension-type headache/cluster headache/other headache types, respectively. The prevalence of migraine and tension-type headache was higher in women than in men but was similar for cluster headache (male vs. female, 1.7% vs. 7.4%, 5.3% vs. 10.8%, and 0.1% vs. 0.1%, respectively). The percentage of individuals with migraine, tension-type headache, cluster headache who had not seen a doctor was 81.0%, 92.0%, 57.1%, respectively. The common headache triggers were fatigue in migraine and tension-type headache, and weather-related phenomena and turning of the seasons in migraine. Common activities refrained from or reduced by headaches were “operating a computer or smartphone”, “drinking alcohol”, and “going to crowded places” in all three headache types and housework-related activities in women. Among individuals taking medicines, 16.8%, 15.8%, 47.6% with migraine, tension-type headache, and cluster headache reported moderate to severe pain, respectively, and 12.6%, 7.7%, 19.0% reported moderate to severe disability, respectively.ConclusionsThis study found various triggers of headache attacks, and daily activities refrained from or reduced by headaches. Additionally, this study suggested that the disease burden in people possibly experiencing tension-type headaches, many of whom had not seen a doctor. The study findings are of clinical value for the diagnosis and treatment of primary headaches.