Updates in the Diagnostic Approach of Headache

In this review, we summarize updates in the diagnostic approach of headaches with the aim of facilitating the distinction between primary and secondary etiology in headaches.

In the USA, headache is the fifth most common complaint in the emergency department, but only a minority will have a secondary etiology. Initial suspicion and diagnostic workup of secondary headache relies on a patient's medical history due to a scarcity of validated biomarkers. A special interest group under the International Headache Society recently synthesized information on red flags (information that indicates a secondary etiology) and green flags (information that indicates a primary etiology). A systematic diagnostic approach using red flags and green flags can help reduce unnecessary testing and shift attention to patient care. Going forward, further validation of these concepts is needed to properly introduce them for clinical use.