Guidelines Reference

Evidence-based recommendations from international headache guidelines

Migraine without Aura
G43.0migraine
Duration: 4-72 hours | Frequency: Variable; chronic if ≥15 days/month for >3 months

ICHD-3 Diagnostic Criteria

  1. AAt least 5 attacks fulfilling criteria B-D
  2. BHeadache attacks lasting 4-72 hours (untreated or unsuccessfully treated)
  3. CHeadache has ≥2 of: unilateral location, pulsating quality, moderate/severe intensity, aggravation by routine physical activity
  4. DDuring headache ≥1 of: nausea and/or vomiting, photophobia and phonophobia
  5. ENot better accounted for by another ICHD-3 diagnosis

Characteristics

UnilateralPulsatingModerate to severeAggravated by activity

Associated Symptoms

Nausea/vomitingPhotophobiaPhonophobiaOsmophobia

Key differentiator: Disabling intensity with nausea and photo/phonophobia. Activity worsens pain. Patient prefers to lie still in dark room.

Source: ICHD-3 (2018); NICE CG150

Migraine with Aura
G43.1migraine
Duration: Aura: 5-60 minutes; Headache: 4-72 hours | Frequency: Affects ~1/3 of migraine sufferers

ICHD-3 Diagnostic Criteria

  1. AAt least 2 attacks fulfilling criteria B and C
  2. B≥1 fully reversible aura symptom: visual, sensory, speech/language, motor, brainstem, retinal
  3. C≥2 of: at least 1 aura symptom spreads gradually over ≥5 minutes; each symptom lasts 5-60 minutes; at least 1 symptom is unilateral; aura accompanied/followed within 60 minutes by headache
  4. DNot better accounted for by another ICHD-3 diagnosis, and TIA excluded

Characteristics

Gradual onset auraVisual symptoms most commonSensory spreadSpeech disturbance possible

Associated Symptoms

Flickering lights/zigzag linesScotomaNumbness/tinglingDysphasia

Key differentiator: Aura develops gradually over ≥5 minutes (vs TIA which is sudden). Visual aura has shimmering/zigzag pattern (vs TIA which is abrupt visual loss).

Source: ICHD-3 (2018); NICE CG150

Tension-Type Headache
G44.2tension
Duration: 30 minutes to 7 days | Frequency: Episodic: <15 days/month; Chronic: ≥15 days/month for >3 months

ICHD-3 Diagnostic Criteria

  1. AAt least 10 episodes occurring on <15 days/month (episodic) or ≥15 days/month for >3 months (chronic)
  2. BHeadache lasting 30 minutes to 7 days
  3. C≥2 of: bilateral location, pressing/tightening quality, mild-moderate intensity, not aggravated by routine physical activity
  4. DBoth: no nausea or vomiting, no more than one of photophobia or phonophobia
  5. ENot better accounted for by another ICHD-3 diagnosis

Characteristics

BilateralPressing/tighteningMild to moderateNot aggravated by activity

Associated Symptoms

Pericranial tenderness possibleNo nausea/vomitingAt most one of photo/phonophobia

Key differentiator: Featureless headache - defined by absence of migraine features. Bilateral, non-pulsating, not worsened by activity, no nausea.

Source: ICHD-3 (2018); NICE CG150

Cluster Headache
G44.0cluster
Duration: 15-180 minutes per attack | Frequency: 1 every other day to 8 per day; bouts last weeks-months with remission periods

ICHD-3 Diagnostic Criteria

  1. AAt least 5 attacks fulfilling criteria B-D
  2. BSevere or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15-180 minutes
  3. CEither or both: ≥1 ipsilateral autonomic symptom (conjunctival injection, lacrimation, nasal congestion, rhinorrhoea, forehead/facial sweating, miosis, ptosis, eyelid oedema); sense of restlessness or agitation
  4. DAttacks have frequency from one every other day to 8 per day
  5. ENot better accounted for by another ICHD-3 diagnosis

Characteristics

Strictly unilateralOrbital/periorbitalVery severe/excruciatingBrief but frequent

Associated Symptoms

LacrimationConjunctival injectionRhinorrhoeaNasal congestionPtosisMiosisRestlessness

Key differentiator: Strictly unilateral, excruciating pain with ipsilateral autonomic features and restlessness. Short duration (15-180 min) but high frequency. Male predominance.

Source: ICHD-3 (2018); NICE CG150; BASH 2019

Medication Overuse Headache
G44.4moh
Duration: Continuous or near-continuous | Frequency: ≥15 days/month for >3 months

ICHD-3 Diagnostic Criteria

  1. AHeadache occurring on ≥15 days/month in a patient with pre-existing headache disorder
  2. BRegular overuse for >3 months of one or more acute headache treatments
  3. CTriptans, opioids, ergots, or combination analgesics on ≥10 days/month
  4. DOR simple analgesics (paracetamol, aspirin, NSAIDs) on ≥15 days/month
  5. ENot better accounted for by another ICHD-3 diagnosis

Characteristics

Daily or near-dailyOften morning headacheDull/oppressiveWorsens with medication use

Associated Symptoms

Anxiety about missing medicationReduced efficacy of acute treatmentIrritability on withdrawal

Key differentiator: Chronic daily headache that developed or worsened during frequent acute medication use. Headache improves after medication withdrawal (may worsen initially for 2-10 days).

Source: ICHD-3 (2018); NICE CG150; BASH 2019

Giant Cell Arteritis (Temporal Arteritis)
M31.6gca
Duration: Continuous, progressive over days to weeks | Frequency: Persistent daily headache (new onset)

ICHD-3 Diagnostic Criteria

  1. AAge ≥50 years at disease onset
  2. BNew headache or new type of localized pain in the head
  3. CTemporal artery abnormality (tenderness, decreased pulsation, or nodularity)
  4. DElevated ESR ≥50 mm/hr and/or elevated CRP
  5. EAbnormal temporal artery biopsy showing necrotizing arteritis with predominant mononuclear cell infiltration or granulomatous inflammation with multinucleated giant cells

Characteristics

Temporal/frontotemporal locationOften unilateral initiallyBoring or burning qualityScalp tenderness (especially when combing hair)Worse at night

Associated Symptoms

Jaw claudicationVisual disturbance (amaurosis fugax, diplopia, sudden visual loss)Scalp tendernessPMR symptoms (shoulder/hip girdle pain and stiffness)Constitutional symptoms (fever, weight loss, malaise, fatigue)Tongue claudication

Key differentiator: New-onset headache in patient >50 with temporal tenderness, jaw claudication, visual symptoms, and elevated inflammatory markers. MEDICAL EMERGENCY due to risk of permanent visual loss. Must start steroids immediately if clinical suspicion is high — do not wait for biopsy.

Source: ICHD-3 (2018); NICE CG150; BASH 2019; ACR/EULAR 2022

Trigeminal Neuralgia (Classical)
G50.0tn
Duration: Fraction of a second to 2 minutes per paroxysm; may occur in volleys | Frequency: Variable: from few attacks to hundreds per day; may have remission periods lasting months to years

ICHD-3 Diagnostic Criteria

  1. ARecurrent paroxysms of unilateral facial pain in the distribution of one or more divisions of the trigeminal nerve, with no radiation beyond
  2. BPain has all of the following characteristics: (a) lasting from a fraction of a second to 2 minutes, (b) severe intensity, (c) electric shock-like, shooting, stabbing, or sharp in quality
  3. CPrecipitated by innocuous stimuli within the affected trigeminal distribution (trigger zones)
  4. DNot better accounted for by another ICHD-3 diagnosis

Characteristics

Strictly unilateral facial painV2 (maxillary) and/or V3 (mandibular) most commonly affectedV1 (ophthalmic) alone is rare (<5%)Electric shock-like, shooting, stabbing qualitySevere to excruciating intensityAbrupt onset and termination

Associated Symptoms

Trigger zones on the face (nasolabial fold, upper lip, lateral nose, chin)Mild autonomic symptoms may occur (tearing, rhinorrhea) during severe attacksAnxiety about triggering attacksWeight loss from avoidance of eating (in severe cases)Ipsilateral facial spasm (tic douloureux) may accompany pain

Key differentiator: Strictly unilateral, brief (seconds to 2 minutes), electric shock-like facial pain in V2/V3 distribution, triggered by innocuous stimuli (light touch, chewing, brushing teeth, cold wind). Pain-free between paroxysms. MRI brain with trigeminal protocol to exclude secondary causes (neurovascular compression, MS, tumour). Distinguished from cluster headache by brevity of attacks and facial (not orbital) distribution.

Source: ICHD-3 (2018) 13.1.1; NICE CG217; AAN/EAN 2019; Cruccu et al. Lancet Neurol 2016