External compression headaches are relatively rare. However, the consultation rate is low and the disease is not well recognized. This report describes a patient who developed intolerable headaches after wearing a helmet at a construction site and required approximately seven months of leave from work. The patient continued to wear the helmet even after the onset of an external compression headache, which worsened. In particular, acute drug treatment is ineffective, resulting in the need for long-term absence. Based on the discrepancy between prevalence and consultation rates, educating occupational workers and workplaces requiring helmet use for external compression headaches is essential.