What is the definition of headache, its etiologies, recommended diagnostic workup, and management?

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Headache: Definition, Causes, Workup, and Management

Definition

Headache is pain or discomfort in the head or face region, classified as either primary (no underlying pathology—migraine, tension-type, cluster) or secondary (caused by an underlying medical condition such as vascular, neoplastic, infectious, or intracranial pressure abnormalities). 1, 2

Causes

Primary Headache Disorders

Tension-type headache is the most common primary headache disorder, affecting approximately 38% of the general population. 1, 2

  • Migraine without aura: Recurrent moderate-to-severe unilateral, pulsating headache lasting 4-72 hours with nausea/vomiting, photophobia, and phonophobia; worsens with routine activity. 3, 1

  • Migraine with aura: Same features as migraine without aura plus recurrent, short-lasting visual and/or hemisensory disturbances that precede or accompany the headache. 3, 1

  • Chronic migraine: ≥15 headache days per month for >3 months, with ≥8 days meeting migraine criteria. 3, 1

  • Tension-type headache: Bilateral, mild-to-moderate pressing/tightening quality; lacks migraine features (no nausea/vomiting, no photophobia plus phonophobia); not aggravated by routine activity. 1, 4

  • Cluster headache: Strictly unilateral severe headache lasting 15-180 minutes with ipsilateral autonomic symptoms (lacrimation, conjunctival injection, nasal congestion, ptosis, miosis); prevalence approximately 0.1% of the population. 1, 4

Secondary Headache Disorders (Red Flags)

Any patient presenting with red flag features requires immediate evaluation for life-threatening secondary causes before considering primary headache disorders. 4, 5

  • Subarachnoid hemorrhage: Thunderclap headache ("worst headache of life"), may have altered taste sensation. 1, 4

  • Meningitis: Headache with neck stiffness and unexplained fever—a life-threatening condition requiring immediate evaluation. 1, 4

  • Brain tumor/space-occupying lesion: Progressive headache, awakens from sleep, worsens with Valsalva/cough. 1, 4

  • Giant cell arteritis: New-onset headache in patients >50 years with scalp tenderness, jaw claudication. 1

  • Stroke/TIA: Atypical aura with focal neurological symptoms. 1

  • Increased intracranial pressure: Headache worsening with coughing, sneezing, exercise. 1

  • Medication-overuse headache: ≥15 headache days/month with regular overuse of acute medications (non-opioid analgesics ≥15 days/month or other acute medications ≥10 days/month) for >3 months. 1

  • Spontaneous intracranial hypotension: Orthostatic headache (absent/mild on waking, onset within 2 hours of upright posture, >50% improvement within 2 hours of lying flat). 1

Workup

History

The medical history is the mainstay of headache diagnosis; a detailed history enables systematic application of the International Classification of Headache Disorders-3 (ICHD-3) criteria. 3, 6

An adequate medical history must include:

  • Age at onset: Migraine typically begins at or around puberty; new-onset headache after age 50 is a red flag. 3, 1, 4

  • Duration of episodes: Migraine 4-72 hours; cluster 15-180 minutes; tension-type variable. 1

  • Frequency: Episodic vs chronic (≥15 days/month). 1

  • Pain location: Unilateral (migraine, cluster) vs bilateral (tension-type). 1

  • Pain quality: Pulsating (migraine) vs pressing/tightening (tension-type) vs severe unilateral (cluster). 1

  • Pain severity: Moderate-to-severe (migraine, cluster) vs mild-to-moderate (tension-type). 1

  • Aggravating factors: Routine activity worsens migraine but not tension-type; Valsalva/cough suggests secondary causes. 1, 4

  • Relieving factors: Lying flat improves orthostatic headache. 1

  • Accompanying symptoms: Nausea/vomiting, photophobia, phonophobia (migraine); autonomic symptoms (cluster). 3, 1

  • Aura symptoms: Visual/hemisensory disturbances lasting <60 minutes. 1

  • Medication use: Acute and preventive medication history for medication-overuse headache. 3, 1

  • Family history: Migraine has a strong genetic component; family history strengthens suspicion. 3, 1

Red Flags Requiring Urgent Investigation

The presence of any red flag mandates immediate evaluation for secondary causes before diagnosing a primary headache disorder. 4, 5

  • Thunderclap headache 1, 4
  • New-onset headache after age 50 1, 4
  • Progressive worsening headache 1, 4
  • Atypical aura (focal neurological symptoms or duration >60 minutes) 1
  • Recent head/neck trauma 1, 4
  • Headache awakening patient from sleep 1, 4
  • Headache brought on by Valsalva, cough, or exertion 1, 4
  • Focal neurological symptoms/signs 1, 4
  • Unexplained fever with neck stiffness or limited neck flexion 1, 4
  • Altered consciousness, memory, or personality 1
  • Witnessed loss of consciousness 1

Physical Examination

Physical examination is most often confirmatory; a normal neurological examination yields a low probability (0.2%) of finding serious intracranial pathology in migraine patients. 3, 1

  • Perform a thorough neurological examination to identify any focal deficits. 3, 4
  • Check for neck stiffness and fever (meningitis). 1, 4
  • Assess for scalp tenderness and jaw claudication in patients >50 years (giant cell arteritis). 1

Diagnostic Aids

Headache diaries are essential for accurate diagnosis, reducing recall bias and allowing systematic application of ICHD-3 criteria over multiple attacks. 3, 6, 4

  • Headache diary: Document frequency, duration, character, triggers, accompanying symptoms, medication use. 3, 1, 6

  • ID-Migraine questionnaire (3-item): Sensitivity 0.81, specificity 0.75, positive predictive value 0.93. 1, 6

  • Migraine Screen Questionnaire (5-item): Sensitivity 0.93, specificity 0.81, positive predictive value 0.83. 1, 6

Investigations

Investigations are only indicated when red flags suggest secondary causes; neuroimaging should not be performed routinely for primary headache disorders with a normal neurological examination. 6, 4

  • MRI brain with and without contrast: Preferred modality for subacute presentations or suspected tumor/inflammatory process; higher resolution, no ionizing radiation. 1, 4

  • Non-contrast CT head: If presenting <6 hours from acute severe headache onset (subarachnoid hemorrhage); sensitivity 95% on day 0,74% on day 3,50% at 1 week. 1

  • CT head: Acute trauma or abrupt-onset headache. 1

  • ESR/CRP: If temporal arteritis suspected (patients >50 years with new-onset headache); note ESR can be normal in 10-36% of giant cell arteritis cases. 1

  • Lumbar puncture: Occasionally required to confirm or reject suspicions of secondary causes (meningitis, subarachnoid hemorrhage if CT negative). 3

Management

Acute Treatment of Migraine

NSAIDs or acetaminophen are first-line for mild-to-moderate migraine attacks. 3, 2

  • Triptans or ergot derivatives: For moderate-to-severe migraine attacks or when NSAIDs fail; triptans eliminate pain in 20-30% of patients by 2 hours but cause transient flushing, tightness, or tingling in 25% of patients. 3, 2

    • Contraindication: Patients with or at high risk for cardiovascular disease should avoid triptans due to vasoconstrictive properties. 2

  • Gepants (rimegepant, ubrogepant): Calcitonin gene-related peptide receptor antagonists; eliminate headache in 20% of patients at 2 hours with adverse effects of nausea and dry mouth in 1-4% of patients. 2

  • Lasmiditan (5-HT1F agonist): Available for acute migraine treatment and appears safe in patients with cardiovascular risk factors. 2

  • Antiemetics: For nausea/vomiting. 3

Acute Treatment of Cluster Headache

High-flow oxygen (100% at 12-15 L/min) is first-line acute treatment for cluster headache. 1

  • Subcutaneous or intranasal triptans: Alternative acute treatment for cluster headache. 1

Preventive Treatment of Migraine

Preventive treatments reduce migraine by 1-3 days per month relative to placebo and should be considered for patients with chronic migraine or frequent episodic migraine. 3, 2

First-line preventive medications include:

  • Beta-blockers (propranolol): 80-240 mg oral daily. 3
  • Anticonvulsants (topiramate): 50-100 mg oral daily. 3

Second-line preventive medications include:

  • Amitriptyline: 10-100 mg oral at night; recommended as first-line for tension-type headache prophylaxis. 3
  • Flunarizine: 5-10 mg oral once daily. 3

Third-line preventive medications include:

  • OnabotulinumtoxinA: 155-195 units to 31-39 sites every 12 weeks. 3
  • Calcitonin gene-related peptide monoclonal antibodies (erenumab, fremanezumab, eptinezumab): Monthly or quarterly dosing. 3, 2

Referral Criteria

Emergency admission is indicated for any red flag present or patient unable to self-care without help. 1, 4

  • Urgent referral to neurology (within 48 hours): Suspected spontaneous intracranial hypotension, patient unable to self-care but has help. 1

  • Routine referral to neurology (2-4 weeks): Suspected primary headache disorder, diagnosis uncertain, first-line treatments fail. 1

  • Referral to rheumatology: Suspected giant cell arteritis. 1

Common Pitfalls

  • Medication-overuse headache: Headache on ≥15 days/month with regular overuse of non-opioid analgesics on ≥15 days/month for ≥3 months, or any other acute medication on ≥10 days/month for ≥3 months, rules out simple episodic migraine and requires withdrawal of overused medications. 1

  • Chronic migraine misdiagnosis: ≥15 headache days/month for >3 months, with ≥8 days meeting migraine criteria, represents chronic migraine—a distinct entity requiring preventive therapy, not just acute treatment. 1

  • Failure to recognize red flags: Always assess for red flags before diagnosing a primary headache disorder; missing a secondary cause can result in significant morbidity and mortality. 4, 5

References

1
Guideline

Approach to Assessment of Headache

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2026

3
Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

4
Guideline

Headache Diagnosis and Management

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2026

6
Guideline

Migraine Diagnosis and Classification

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

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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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