Red flags include recent onset, rapidly increasing frequency and severity of headache; headache causing the patient to wake from sleep; associated dizziness, lack of coordination, tingling or numbness, new neurologic deficit; and new onset of a headache in a patient with a history of cancer or immunodeficiency.
Sources:
Beithon J, et al. Institute for clinical systems improvement. Diagnosis and treatment of headache [Internet]. 2013 Jan [cited 2017 May 5].
Choosing Wisely. American College of Radiology: Five things physicians and patients should question [Internet]. 2012 Apr 4 [cited 2017 May 5].
Edlow JA, et al. Clinical policy: Critical issues in the evaluation and management of adult patients presenting to the emergency department with acute headache. Ann Emerg Med. 2008 Oct;52(4):407-36. PMID: 18809105.
Hayes LL, et al. ACR appropriateness criteria®: Headache – child [Internet]. 2012 [cited 2014 Feb 23].
Health Quality Ontario. Neuroimaging for the evaluation of chronic headaches: An evidence-based analysis. Ont Health Technol Assess Ser. 2010;10(26):1-57. PMID: 23074404.
Jordan YJ, et al. Computed tomography imaging in the management of headache in the emergency department: Cost efficacy and policy implications. J Natl Med Assoc. 2009 Apr;101(4):331-5. PMID: 19397223.
National Institute for Health and Clinical Excellence (NICE). Headaches: Diagnosis and management of headaches in young people and adults [Internet]. 2012 Sep [2017 May 5].
Sandrini G, et al. Neurophysiological tests and neuroimaging procedures in non-acute headache (2nd edition). Eur J Neurol. 2011 Mar;18(3):373-81. PMID: 20868464.
Scottish Intercollegiate Guidelines Network (SIGN). Diagnosis and management of headache in adults: A national clinical guideline [Internet]. 2008 Nov [2017 May 5].
Toward Optimized Practice. Guideline for primary care management of headache in adults [Internet]. 2016 Sep [2017 May 5].
Related Resources:
Patient Pamphlet: Imaging Tests for Headaches: When you need them and when you don’t