What are the primary and secondary headache types, their distinguishing features, and recommended acute and preventive management?

Types of Headache: Classification and Clinical Approach

Primary vs. Secondary Headache Disorders

Headaches are classified into primary disorders (migraine, tension-type, cluster) that have no underlying pathology, and secondary disorders caused by identifiable medical conditions—primary headaches account for approximately 90% of presentations, with tension-type affecting 38% and migraine affecting 12-18% of the population. 1, 2, 3

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Primary Headache Types

Migraine Without Aura

Diagnosis requires ≥5 lifetime attacks lasting 4-72 hours, with ≥2 pain characteristics (unilateral, pulsating, moderate-to-severe intensity, or worsened by routine activity) AND ≥1 associated feature (nausea/vomiting OR both photophobia and phonophobia). 2, 4

• Pain characteristics: Unilateral location in most cases, pulsating/throbbing quality, moderate-to-severe intensity that interferes with daily activities 2, 4
• Key distinguishing features: Photophobia combined with nausea strongly supports migraine over other primary headaches 2
• Duration: Individual attacks last 4-72 hours if untreated 1, 2
• Prevalence: Affects 18% of women and 6.5% of men in the United States 4

Migraine With Aura

Requires all features of migraine without aura PLUS recurrent visual/sensory/speech disturbances with ≥3 characteristics: gradual spread over ≥5 minutes, ≥2 symptoms in succession, ≥1 unilateral symptom, ≥1 positive symptom, and aura followed by headache within 60 minutes. 2

• Critical red flag: Atypical aura lasting >60 minutes or with focal neurological deficits may indicate stroke/TIA and requires urgent neuroimaging 2

Chronic Migraine

Defined as ≥15 headache days/month for >3 months, with ≥8 days meeting migraine criteria—this represents a distinct entity requiring preventive therapy and neurology referral. 2, 4

Tension-Type Headache

Bilateral, pressing/tightening (non-pulsating) pain of mild-to-moderate intensity, NOT aggravated by routine activity, and lacking both nausea/vomiting AND the combination of photophobia plus phonophobia. 2, 4

• Prevalence: Most common primary headache at 38% of the population 2, 3
• Key differentiator: Absence of migraine features—no nausea, no worsening with activity, bilateral location 2, 4

Cluster Headache

Strictly unilateral severe-to-very-severe pain lasting 15-180 minutes, occurring 1-8 times daily, with ipsilateral autonomic symptoms (lacrimation, conjunctival injection, nasal congestion, ptosis, miosis). 2, 4

• Prevalence: Rare at ~0.1% of the population 2, 4
• Attack frequency: Requires ≥5 attacks meeting criteria for diagnosis 4

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Secondary Headache Types and Red Flags

Life-Threatening Causes Requiring Immediate Evaluation

Any patient presenting with thunderclap headache ("worst headache of life"), focal neurological signs, unexplained fever with neck stiffness, altered consciousness, or new-onset headache after age 50 requires emergency evaluation for secondary causes. 2, 4

Subarachnoid Hemorrhage

• Presentation: Thunderclap onset, may have altered taste sensation 2
• Imaging: Non-contrast CT within 6 hours has 95% sensitivity (drops to 74% by day 3,50% at 1 week) 2

Meningitis

• Presentation: Headache with neck stiffness and unexplained fever—requires immediate evaluation 2, 4

Brain Tumor/Space-Occupying Lesion

• Presentation: Progressive headache, awakens from sleep, worsens with Valsalva/cough 2
• Pediatric note: Nearly all children with intracranial tumors have additional neurologic signs (94% had abnormal findings, 60% had papilledema) 1

Giant Cell Arteritis

• Presentation: New-onset headache in patients >50 years with scalp tenderness, jaw claudication 2
• Caveat: ESR can be normal in 10-36% of cases 2

Increased Intracranial Pressure

• Presentation: Headache worsening with coughing, sneezing, exercise 2

Spontaneous Intracranial Hypotension

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

Medication-Overuse Headache

Defined as ≥15 headache days/month with regular overuse of non-opioid analgesics ≥15 days/month OR other acute medications ≥10 days/month for >3 months—this transforms episodic migraine into a chronic daily headache pattern. 2

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Diagnostic Approach

History Elements That Determine Headache Type

• Age at onset: Migraine typically begins at/around puberty 2
• Duration: Migraine 4-72 hours; cluster 15-180 minutes; tension-type variable 2
• Location: Unilateral (migraine, cluster) vs bilateral (tension-type) 2, 4
• Quality: Pulsating (migraine) vs pressing/tightening (tension-type) vs severe unilateral (cluster) 2, 4
• Aggravating factors: Routine activity worsens migraine but not tension-type 2, 4

Validated Screening Tools

• ID-Migraine questionnaire (3-item): Sensitivity 0.81, specificity 0.75, positive predictive value 0.93 2
• Migraine Screen Questionnaire (5-item): Sensitivity 0.93, specificity 0.81, positive predictive value 0.83 2
• Headache diary: Document frequency, duration, character, triggers, accompanying symptoms, medication use to reduce recall bias 2, 4

Neuroimaging Indications

Neuroimaging is NOT routinely indicated for primary headaches with normal neurological examination—the yield is only 0.2% (2/1086 patients), no higher than 0.4% in asymptomatic volunteers. 2

MRI with and without contrast is preferred for subacute presentations or suspected tumor/inflammatory processes; non-contrast CT is indicated only if presenting <6 hours from acute severe headache onset (subarachnoid hemorrhage). 2, 5

• Pediatric imaging: Yield of brain MRI is not contributory in children with primary headache and normal examination (<1% had relevant findings) 1
• No role for CTA, CTV, MRA, MRV, or arteriography in primary headache without concerning examination findings 1

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Acute Management by Headache Type

Migraine Acute Treatment

NSAIDs or acetaminophen are first-line for all migraine attacks, including severe attacks that have responded to these agents previously; triptans or ergot derivatives are indicated for moderate-to-severe attacks or when NSAIDs fail. 1, 2

• NSAIDs with strongest evidence: Aspirin, ibuprofen, naproxen sodium, tolfenamic acid, and combination acetaminophen-aspirin-caffeine 1
• Acetaminophen alone is ineffective 1
• Triptans: Oral naratriptan, rizatriptan, sumatriptan, zolmitriptan; subcutaneous/intranasal sumatriptan for patients with nausea/vomiting 1
• Triptan efficacy: Eliminate pain in 20-30% of patients by 2 hours 3
• Triptan adverse effects: Transient flushing, tightness, or tingling in upper body in 25% of patients; contraindicated in cardiovascular disease due to vasoconstrictive properties 3
• Gepants (rimegepant, ubrogepant): Eliminate headache in 20% at 2 hours; adverse effects include nausea and dry mouth in 1-4% 3
• Lasmiditan (5-HT1F agonist): Safe in patients with cardiovascular risk factors 3
• Antiemetics: For nausea/vomiting 2

Cluster Headache Acute Treatment

High-flow oxygen (100% at 12-15 L/min) is first-line acute treatment; subcutaneous or intranasal triptans are alternative acute treatments. 2

Preventive Treatment Indications

Preventive therapy is indicated for chronic migraine (≥15 headache days/month) and reduces migraine frequency by 1-3 days per month relative to placebo. 2, 3

• Options: Antihypertensives, antiepileptics, antidepressants, calcitonin gene-related peptide monoclonal antibodies, onabotulinumtoxinA 3

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Referral Pathways

• Emergency admission: Any red flag present, patient unable to self-care without help 2
• Urgent neurology referral (within 48 hours): Suspected spontaneous intracranial hypotension, patient unable to self-care but has help 2
• Routine neurology referral (2-4 weeks): Suspected primary headache disorder, diagnosis uncertain, first-line treatments fail 2
• Rheumatology referral: Suspected giant cell arteritis 2

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Common Pitfalls

• "Sinus headache" misdiagnosis: Approximately 62% of pediatric migraineurs have cranial autonomic symptoms (rhinorrhea) from trigeminal-autonomic reflex activation—consider migraine before sinusitis 1
• Overlooking medication-overuse: Regular use of acute medications transforms episodic into chronic headache—requires withdrawal and preventive therapy 2
• Imaging normal-exam primary headaches: Wastes resources and exposes patients to unnecessary radiation/contrast without changing management 1, 2
• Missing giant cell arteritis: Normal ESR in 10-36% of cases—clinical suspicion in patients >50 with new headache should prompt rheumatology referral regardless 2