Acute headache: diagnosis

Stephanie J Nahas MD (Dr. Nahas of Thomas Jefferson University received honorariums from Allergan, Amgen, Electrocore, Eli Lilly, and Supernus for consulting work, and from Amgen for speaking engagements.)
Stephen D Silberstein MD, editor. (

Dr. Silberstein, Director of the Jefferson Headache Center at Thomas Jefferson University, receives honorariums from Allergan, Avanir Pharmaceuticals, Curelator, Depomed, Dr. Reddy's Laboratories, eNeura,  INSYS Therapeutics, Lilly USA, Supernus Pharmacerticals,  Thernica and Trigemina for consulting. He is also the  principal investigator for a clinical trials conducted by Alder Biopharmaceuticals, Amgen, electroCore Medical, Lily USA and Teva.

Originally released October 21, 2004; last updated December 4, 2017; expires December 4, 2020

This article incudes discussion of diagnosis of acute headache; migraine; thunderclap headache; tension-type headache; headache with systemic illness or systemic symptoms; migraine aura; headache triggered by cough, exertion, or orgasm; headache during pregnancy or postpartum; positional headache; headache in the elderly; sinus symptoms and headache; and ocular disorders. The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations.


Headache is a common chief complaint in acute settings. The diagnosis of acute headache can be challenging and should proceed in an orderly fashion. An important first step is to distinguish primary from secondary headaches. The approach is to seek “red flags” that suggest the possibility of secondary headache. If 1 of these features is identified, the physician must conduct the workup indicated by the red flag and, thereby, diagnose any secondary headache disorder that is present. In the absence of secondary headache, the clinician proceeds to diagnosing a primary headache disorder. In this article, the author follows this approach to discuss the differential diagnosis of acute headaches.

Key points


• Migraine is the most common diagnosis in the evaluation of acute headache.


• Secondary causes must be ruled out in all cases of acute headache presentation, mainly based on “red flags” uncovered in the history and physical/neurologic examination.


• A systematic approach to the headache, characterizing it in terms of duration, quality, location, and accompanying symptoms, speeds the diagnosis.

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