What are the red flags for headache diagnosis?

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From the Guidelines

Headache red flags are clinical indicators that suggest the presence of a potentially serious underlying condition, warranting prompt medical evaluation.

Red Flags

These red flags include:

  • Thunderclap headache, which is a sudden onset of a severe headache, often described as "the worst headache of my life" 1
  • Atypical aura, which can be a symptom of transient ischemic attack, stroke, epilepsy, or arteriovenous malformations 1
  • Headache accompanied by unexplained fever, which can be a sign of meningitis 1
  • Headache with focal neurological symptoms, such as impaired memory, altered consciousness, or personality changes, which can suggest a secondary headache disorder 1
  • Headache that worsens over time or is triggered by exertion or cough, which can be a sign of an intracranial space-occupying lesion or other serious conditions 1
  • Head trauma, which can be a cause of subdural hematoma or other serious conditions 1
  • Progressive headache, which can be a sign of an intracranial space-occupying lesion or other serious conditions 1
  • Headache onset at >50 years of age, which can suggest a secondary headache disorder, such as temporal arteritis 1 Patients presenting with these red flags should undergo a thorough neurological examination and may require diagnostic imaging, such as computed tomography (CT) or magnetic resonance imaging (MRI), to rule out conditions like subarachnoid hemorrhage or meningitis 1.

From the FDA Drug Label

Before treating headaches in patients not previously diagnosed as migraineurs, and in migraineurs who present with atypical symptoms, exclude other potentially serious neurological conditions. Cerebral hemorrhage, subarachnoid hemorrhage, and stroke have occurred in patients treated with 5-HT1 agonists, and some have resulted in fatalities In a number of cases, it appears possible that the cerebrovascular events were primary, the 5-HT1 agonist having been administered in the incorrect belief that the symptoms experienced were a consequence of migraine when they were not. Also, patients with migraine may be at increased risk of certain cerebrovascular events (e.g., stroke, hemorrhage, TIA). Sumatriptan tablets are contraindicated in patients with a history of stroke or TIA.

The red flags for headache diagnosis include:

  • Atypical symptoms in patients with a history of migraine
  • Cerebrovascular events such as cerebral hemorrhage, subarachnoid hemorrhage, and stroke
  • History of stroke or TIA
  • Unusual or sudden onset of headache symptoms
  • Headache with associated neurological symptoms such as confusion, seizures, or loss of consciousness These red flags indicate the need for further evaluation to exclude other potentially serious neurological conditions 2, 3.

From the Research

Red Flags for Headache Diagnosis

The following are red flags for headache diagnosis:

  • Focal neurologic signs 4, 5, 6, 7, 8
  • Papilledema 4, 5, 6, 8
  • Neck stiffness 4
  • Immunocompromised state 4, 8
  • Sudden onset of the worst headache in the patient's life 4, 5, 6, 8
  • Personality changes 4
  • Headache after trauma 4, 5, 6, 8
  • Headache that is worse with exercise 4, 6
  • Onset of headache after 50 years of age 5, 6, 8
  • Increased frequency or severity of headache 5
  • New onset of headache with an underlying medical condition 5
  • Headache with concomitant systemic illness 5
  • Headache subsequent to head trauma 5
  • Recent head or neck injury 6
  • Headache brought on by Valsalva maneuver or cough 6
  • Headache brought on by exertion 6
  • Headache associated with sexual activity 6
  • Pregnancy 6, 8
  • Neurologic findings and/or symptoms 6, 7
  • Systemic signs and/or symptoms 6, 7
  • Secondary risk factors, such as cancer or human immunodeficiency virus (HIV) infection 6, 8

Diagnostic Testing

Diagnostic testing, including neuroimaging, cerebrospinal fluid (CSF) examination, and blood tests, may be necessary to evaluate the cause of headache in patients with red flags 4, 5, 6, 7, 8. The choice of diagnostic test depends on the patient's history and findings 6, 7, 8.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Approach to acute headache in adults.

American family physician, 2013

Research

Evaluation of acute headaches in adults.

American family physician, 2001

Research

Headache Disorders: Differentiating Primary and Secondary Etiologies.

Journal of integrative neuroscience, 2024

Research

ACR Appropriateness Criteria® Headache.

Journal of the American College of Radiology : JACR, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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