Headache
Headache Disorders: Overview and Classification
Primary Headache Disorders
Migraine
- Epidemiology: Female predominance; often begins in adolescence; strong family history
- Clinical Features:
- Recurrent, unilateral throbbing headache
- Duration: 4–72 hours
- Associated symptoms:
- Visual, sensory, motor or cortical aura (in some subtypes)
- Gastrointestinal: nausea and vomiting
- Photophobia and phonophobia
- Often triggered by predictable factors (e.g. hormonal changes, stress, sleep deprivation)
Episodic Tension-Type Headache
- Epidemiology: More evenly distributed across sexes; often begins in early adulthood
- Clinical Features:
- Bilateral, band-like or pressing pain
- Mild to moderate intensity
- No associated nausea, photophobia or phonophobia
- No aura
- Not usually disabling
Cluster Headache
- Epidemiology: Strong male predominance; age of onset typically 20–40 years
- Clinical Features:
- Severe, unilateral periorbital or temporal pain (“suicidal headache”)
- Duration: 15–180 minutes
- Occurs in clusters (e.g. daily for weeks/months, then remission)
- Ipsilateral autonomic features: lacrimation, nasal congestion, ptosis, conjunctival injection
- Alcohol can trigger attacks during a cluster period
Trigeminal Autonomic Cephalalgias (TACs)
- Includes:
- Cluster headache
- Paroxysmal hemicrania
- Short-lasting unilateral neuralgiform headache attacks (SUNCT/SUNA)
- Characterised by unilateral pain with cranial autonomic features
Primary Chronic Daily Headache Disorders
- Transformed Migraine: Evolved from episodic migraine; may lose classic features
- Chronic Tension-Type Headache: Most common chronic headache; daily, bilateral, pressing
- New Daily Persistent Headache (NDPH): Abrupt onset of daily headache; persistent from onset
- Hemicrania Continua:
- Continuous, unilateral headache responsive to indomethacin
- Associated with autonomic symptoms
Secondary Headache Disorders
Due to Local Pathology
- Skull: Paget’s disease, metastases, mastoiditis
- Ear: Otitis media or externa
- Eye: Glaucoma, strabismus, refractive errors, iritis
- Nose/Sinuses: Acute or chronic sinusitis
- Teeth: Dental abscess, malocclusion
- Cervical Spine: Cervical spondylosis
- Cranial Nerves: Occipital neuralgia, herpes zoster
Due to Intracranial or Systemic Disorders
- Intracranial vascular: Ruptured aneurysm, venous sinus thrombosis, haemorrhage
- Extracranial vascular: Carotid dissection, temporal arteritis
- CSF pressure disorders: Intracranial hypertension or hypotension (e.g. post-lumbar puncture)
- Intracranial infections: Meningitis, encephalitis
- Systemic infections: Influenza, typhoid, malaria
- Medications: Nitroglycerin, PDE inhibitors, overuse headaches
- Other: Hypertensive crisis, pituitary apoplexy
Red Flag Features in Headache (“SNOOP” and others)

Mnemonic / Context | Red Flag Feature | Examples / Clinical Concern | Possible Diagnosis / Concern |
---|---|---|---|
S – Systemic signs/symptoms | Constitutional symptoms – fever – weight loss – myalgia – rash – anorexia | Headache + systemic infection signs elevated ESR/CRP | Meningitis encephalitis vasculitis GCA HIV systemic malignancy |
N – Neurologic symptoms | Focal deficits cranial nerve palsy seizures altered LOC confusion | Weakness, sensory change diplopia new seizure | Stroke mass lesion brain abscess metastatic disease |
O – Onset (sudden) | Sudden “thunderclap” headache reaches peak within seconds to minutes | Worst-ever headache abrupt onset | Subarachnoid haemorrhage (SAH) venous sinus thrombosis arterial dissection |
O – Older age or new pattern | Age >50 with new headache OR a change in usual headache pattern | Persistent unilateral temple headache new visual symptoms | Giant cell arteritis glaucoma intracranial mass |
P – Progressive course | Headache worsening over time in frequency OR intensity OR duration | Increasing medication need spreading symptoms | Brain tumour metastases raised ICP |
P – Positional / Precipitants / Papilloedema | Headache worsens with posture or Valsalva OR associated with papilloedema | Worse on standing (CSF leak) worse lying down or coughing (↑ ICP) | Intracranial hypotension idiopathic intracranial hypertension mass effect |
Additional Urgent Contexts (Beyond SNOOPP)
Clinical Context | Red Flag Presentation | Suggested Diagnosis / Concern |
---|---|---|
Known malignancy | New headache in cancer patient | CNS metastases carcinomatous meningitis |
Immunocompromised (e.g. HIV) | New headache | Opportunistic infection: – cryptococcus – toxoplasmosis – TB meningitis |
Post-trauma / neck manipulation | Headache following minor trauma or chiropractic manipulation | Subdural haematoma vertebral artery dissection |
Persistent focal signs | Neurological signs that precede or persist beyond headache | Mass lesion stroke hemiplegic migraine (rare) |
Headache with rash | Systemic illness + rash | Meningococcal meningitis Lyme disease |
Visual disturbances | Pressing pain with visual changes | Glaucoma optic neuritis temporal arteritis |
Pregnancy / Postpartum | New non-migraine headache in pregnancy or shortly after | Cerebral venous sinus thrombosis Preeclampsia Pituitary apoplexy |
Triggered by Valsalva (cough/strain) | Headache worsened by straining, bending, sneezing | SAH Posterior fossa mass |
Postural trigger | Worse on standing or sitting; relieved lying down | CSF leak (spontaneous or post-lumbar puncture) |
Unusual features for primary headache | Atypical aura, duration, location, age of onset | Consider secondary cause even if initially resembles migraine |
Blue flag features :
Definition: Blue flag features suggest a secondary cause of headache that typically does not require urgent investigation or hospital referral.
These contrast with red flag features, which warrant immediate or expedited evaluation for potentially life-threatening pathology.
Examples of Blue Flag Features
Feature | Possible Cause | Clinical Consideration |
---|---|---|
Headache predominantly occipital, sometimes radiating to the temples, worsened by neck movement | Cervicogenic headache or cervical spondylosis | Often posture-related; responds to physiotherapy, analgesia |
Headache temporally related to recent whiplash injury | Post-traumatic or cervicogenic headache | May persist for days to weeks; monitor for evolving red flag signs |
Headache triggered by prolonged reading or screen use | Ocular strain or uncorrected refractive error | Consider optometry review; not urgent unless vision loss |
Headache occurring shortly after ingestion of certain medications (e.g. nitrates, PDE-5 inhibitors) | Medication-induced headache | Reversible with cessation; education and monitoring |
Headache associated with a systemic viral illness (e.g. influenza, COVID-19) | Febrile illness-related headache | Common and self-limited; watch for signs of meningitis or encephalitis if persistent/severe |
quick differentials…..
Type | Site | Features | Causes | Management | Other |
Tension Headache | Symmetrical, tight | Non-pulsating No nausea No vomiting | Stress, tension, cervical dysfunction | Relaxation, meditation Massage Simple analgesia | 75% female |
Cervical Dysfunction /Spondylosis | Occipital with radiation to parietal region, vertex, eye | Present on waking and settles Tender over C1-3 levels on side of headache | Abnormalities in C2/3 innervated structure, facet joint arthropathy | Physiotherapy Supportive neck pillow NSAIDs Corticosteroid injection | History of MVA/trauma |
Cluster headache | Unilateral over or around eye | Wakes at same time, 1-3 times per day at same time in 6 week clusters | Vascular: dilation of blood vessels | 100% O2 for acute attack Prevention: verapamil, lithium, methysergide Steroids rapidly suppress attacks | Alcohol aggravatingRetro-orbital headache +rhinorrhoea + lacrimation = cluster headache |
Temporal arteritis | Temporal region and forehead | Severe burning pain, malaise, vague aches and painsESR elevatedJaw claudicationIntermittent blurred vision | Inflammation temporal artery Ophthalmic and post. Ciliary arteries can be involved leading to optic atrophy and blindness | Steroids: start immediately to prevent blindness Pred 60mg daily | 50-70yo PMR 20% patients get TA May take 1-2 years to resolve |
Raised intracranial pressure | Generalised, often occipital | Worse in mornings, intermittent Vomiting Vertigo Seizures drowsiness | Intracerebral tumour, subdural haematoma | Imaging and refer | Drowsiness + vomiting + seizure = raised ICP |
Frontal sinusitis | Frontal or retro-orbital | Worse in mornings Focal facial tenderness Otitis media | Commonly post URTI | Steam inhalations Amoxil Analgesia | |
Subarachnoid Haemorrhage | Occipital | Sudden onset, neck pain and stiffnessVomiting, Kernig sign +Neurological deficit | Ruptured aneurysm | CT investigation and immediate referral | Occipital Headache + vomiting + neck stiffness =SAH |
