What are the differential diagnoses for headache accompanied by nausea?

Differential Diagnoses for Headache with Nausea

Headache accompanied by nausea most commonly indicates migraine, but you must immediately rule out life-threatening secondary causes—particularly subarachnoid hemorrhage, meningitis, cerebral venous thrombosis, and intracranial mass lesions—before diagnosing a primary headache disorder. 1, 2

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Algorithmic Approach to Headache with Nausea

Step 1: Screen for Red-Flag Features (Immediate Imaging/Workup Required)

Any of the following mandate urgent evaluation:

Historical Red Flags

• Thunderclap onset (maximum intensity within seconds to minutes) → suspect subarachnoid hemorrhage or cerebral venous thrombosis; obtain non-contrast CT head immediately 2
• Recent head trauma within 2–7 days → requires urgent neuroimaging 2
• Rapidly increasing headache frequency over days to weeks → suggests evolving intracranial pathology 2
• Headache awakening patient from sleep → concerning for secondary cause 2
• Marked change in previously stable headache pattern → warrants immediate investigation 2
• Atypical aura (>60 minutes duration, motor weakness, or sudden simultaneous onset) → may represent stroke or arterial dissection 2

Physical Examination Red Flags

• Focal neurological deficits (hemiparesis, aphasia, sensory loss, visual field defects) → demand immediate neuroimaging 2
• Papilledema on fundoscopy → indicates raised intracranial pressure from mass, venous thrombosis, or idiopathic intracranial hypertension 2
• Unexplained fever → raises suspicion for meningitis, encephalitis, or parameningeal infection 2
• Neck stiffness (meningismus) with fever → points toward meningitis or subarachnoid hemorrhage; requires immediate imaging and lumbar puncture if indicated 2
• Altered mental status or impaired consciousness → emergency indication for urgent imaging 2
• Uncoordinated movements (ataxia, dysmetria) → increases likelihood of positive imaging study 2

If any red flag is present: Proceed directly to neuroimaging. MRI is preferred for most secondary headache evaluations due to superior resolution and lack of ionizing radiation, except in acute settings (thunderclap headache, suspected hemorrhage) where non-contrast CT is first-line. 2

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Step 2: If No Red Flags—Differentiate Primary Headache Disorders

When neurological examination is normal and no red flags exist, neuroimaging is not indicated (yield is only 0.2% in migraine, comparable to 0.4% in asymptomatic individuals). 2

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Primary Headache Differentials (When Nausea is Present)

1. Migraine Without Aura (Most Likely)

Migraine is the most common primary headache disorder presenting with nausea. 1

Diagnostic Criteria (Requires ≥5 Attacks):

• Duration: 4–72 hours when untreated 1
• Pain characteristics (≥2 of the following):
  • Unilateral location (though 40% report bilateral pain—do not exclude migraine based on bilaterality alone) 1
  • Pulsating quality 1
  • Moderate to severe intensity 1
  • Aggravation by routine physical activity (walking, climbing stairs) 1
• Associated symptoms (≥1 required):
  • Nausea and/or vomiting 1
  • Photophobia AND phonophobia 1

Additional Features:

• Prodromal symptoms (before pain onset): depressed mood, yawning, fatigue, food cravings 1
• Postdromal symptoms (after headache resolves): tiredness, concentration difficulties, neck stiffness lasting up to 48 hours 1
• Strong family history of migraine is common 1

Clinical Pearl: Nausea is so characteristic of migraine that it forms part of the validated ID-Migraine screening tool (3 items: nausea, photophobia, disability; sensitivity 0.81, specificity 0.75). 2

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2. Migraine With Aura

Approximately one-third of migraine patients experience aura with some or all attacks. 1

Diagnostic Criteria (Requires ≥2 Attacks):

• Aura symptoms (≥1 of the following, fully reversible):
  • Visual (>90% of auras): fortification spectra, scintillating scotomas 1
  • Sensory (≈31% of auras): gradual spreading unilateral paresthesia in face or arm 1
  • Speech/language, motor, brainstem, or retinal symptoms 1, 3
• Aura characteristics (≥3 of the following):
  • ≥1 symptom spreads gradually over ≥5 minutes 1, 3
  • Two or more symptoms occur in succession 1, 3
  • Each symptom lasts 5–60 minutes 1, 3
  • ≥1 symptom is unilateral 1, 3
  • ≥1 symptom is positive (scintillations, pins and needles) 1, 3
  • Aura is accompanied or followed by headache within 60 minutes 1, 3
• Headache phase meets criteria for migraine without aura (including nausea) 1, 3

Critical Pitfall: True migraine aura develops gradually over ≥5 minutes; sudden onset or prolonged aura (>60 minutes) requires urgent stroke evaluation. 2

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3. Chronic Migraine

Defined as ≥15 headache days per month for >3 months, with migraine criteria met on ≥8 days per month. 1

• Nausea remains a prominent feature on migraine days 1
• Key differential: Medication-overuse headache (see below) 1

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4. Medication-Overuse Headache (MOH)

A secondary headache disorder that commonly complicates chronic migraine. 1

Diagnostic Criteria:

• Headache ≥15 days per month in a patient with pre-existing headache disorder 1
• Regular overuse for >3 months of:
  • Non-opioid analgesics on ≥15 days/month, OR 1
  • Triptans, ergots, opioids, or combination medications on ≥10 days/month 4, 1

Clinical Pearl: MOH can mask an evolving secondary cause; do not dismiss red-flag features in the context of medication overuse. 2

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5. Cluster Headache (Less Likely with Nausea)

Cluster headache affects ≈0.1% of the population and is less commonly associated with nausea than migraine. 1

Diagnostic Criteria:

• Strictly unilateral pain lasting 15–180 minutes per attack 1
• Severe to very severe intensity 1
• Ipsilateral cranial autonomic symptoms (conjunctival injection, lacrimation, nasal congestion, ptosis, miosis, eyelid edema) 1
• Frequency: 1–8 attacks per day during cluster periods 2

Important Note: While cluster headache is primarily distinguished by autonomic features, 24.5% of cluster patients experience migraine-like features including nausea during attacks. 5 However, nausea is not a defining feature and its presence does not influence diagnosis or treatment. 5

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6. Tension-Type Headache (Unlikely with Nausea)

Tension-type headache typically lacks nausea, which helps differentiate it from migraine. 1

Diagnostic Criteria:

• Bilateral location 1
• Pressing or tightening (non-pulsatile) quality 1
• Mild to moderate intensity 1
• Not aggravated by routine physical activity 1
• Absence of migraine-associated symptoms (no photophobia, phonophobia, or nausea) 1

If nausea is present with otherwise tension-type features, reconsider the diagnosis toward migraine. 1

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Secondary Headache Differentials (Life-Threatening—Rule Out First)

1. Subarachnoid Hemorrhage (SAH)

• Presentation: Thunderclap headache (sudden, severe, "worst headache of life") with nausea/vomiting 2
• Imaging: Urgent non-contrast CT has ≈98% sensitivity and ≈99% specificity for acute SAH 2
• If CT negative but suspicion high: Lumbar puncture ≥12 hours after onset to assess for xanthochromia 2

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2. Meningitis/Encephalitis

• Presentation: Headache with fever, neck stiffness, nausea/vomiting 1, 2
• Workup: Lumbar puncture required when meningitis is suspected 1, 2

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3. Cerebral Venous Thrombosis (CVT)

• Presentation: Diffuse, progressive headache over days to weeks with nausea; may have focal deficits (hemiparesis, aphasia, seizures) 2, 6
• Critical Pitfall: ≈25% of CVT patients present with isolated headache lacking papilledema or focal deficits—do not dismiss based on normal exam alone 2
• Imaging: MRI preferred over CT for detection 2
• Special populations: Higher risk in pregnancy/postpartum period and with parameningeal infections (mastoiditis, sinusitis) 2, 6

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4. Intracranial Mass/Tumor

• Presentation: Progressive headache pattern with nausea, often accompanied by neurological deficits 2
• Imaging: MRI preferred for detection 2

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5. Arterial Dissection

• Presentation: Sudden, severe unilateral headache with nausea; may have Horner syndrome 2
• Imaging: MRI more sensitive than CT for detecting arterial dissection 2

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6. Cardiac Cephalgia (Rare)

• Presentation: Severe headache with nausea, worsened by physical exercise, only ceases with nitrate administration 7
• Population: Patients with known ischemic heart disease 7
• Critical Pitfall: Differential diagnosis with migraine is crucial to avoid administering vasoconstrictors (triptans) 7

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Acute Management Considerations (When Migraine is Diagnosed)

For severe nausea or vomiting with migraine:

• Consider using a nonoral triptan and an antiemetic 4
• First-line acute treatment: NSAIDs (aspirin, ibuprofen, diclofenac) or acetaminophen 4, 1
• Second-line: Add a triptan to an NSAID (or acetaminophen if NSAIDs contraindicated) 4
• Do not use opioids or butalbital for acute episodic migraine 4

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Summary Algorithm

1. Screen for red flags → If present: urgent imaging/workup
2. If no red flags:
   • Duration 4–72 hours + unilateral/pulsating/moderate-severe pain + nausea/photophobia/phonophobia → Migraine
   • Duration 15–180 minutes + strictly unilateral severe pain + autonomic symptoms → Cluster headache (nausea less common)
   • Bilateral pressing pain + no associated symptoms → Tension-type headache (nausea excludes this diagnosis)
3. Assess headache frequency:
   • ≥15 days/month for >3 months → Consider chronic migraine or medication-overuse headache
4. Review medication use:
   • Overuse of acute medications (≥15 days/month NSAIDs; ≥10 days/month triptans) → Medication-overuse headache

4, 1, 2