🩺 Headache

Headache is one of the most common presentations in both primary care and emergency departments. While the majority are primary headache disorders (migraine, tension, or cluster), clinicians must remain vigilant for secondary causes that are life- or sight-threatening. The clinical priority is identifying 'red flags' that suggest underlying pathology such as intracranial haemorrhage, infection, malignancy, or vasculitis. Understanding the temporal profile (acute, subacute, or chronic) is key to narrowing the differential. Management ranges from lifestyle advice and simple analgesia to neurosurgical intervention.

Elicit the speed of onset, duration, and frequency of episodes. A 'thunderclap' onset (maximal intensity within seconds to minutes) is a red flag for subarachnoid haemorrhage. Enquire about associated symptoms like photophobia, phonophobia, nausea, and vomiting. Distinguish between primary types: Migraine (unilateral, throbbing, aura), Tension-type (bilateral, band-like, non-disabling), and Cluster (unilateral, periorbital, autonomic features). Ask about triggers, such as physical exertion, posture changes, or specific foods. Screens for systemic symptoms like weight loss or jaw claudication are essential in older populations.

Assessment begins with vital signs, specifically blood pressure to rule out hypertensive emergency and temperature for meningitis. Neurological examination must include fundoscopy to identify papilloedema or retinal haemorrhages. Perform a full cranial nerve exam, looking for third or sixth nerve palsies (false localising signs). Assess for meningism through neck stiffness, Kernig's, and Brudzinski's signs. Temporal arteries should be palpated for tenderness and pulsation in patients over 50. A focused peripheral neurological exam should check for focal deficits, ataxia, or pronator drift.

Subarachnoid Haemorrhage (SAH), Migraine, Tension-type headache, Cluster headache, Giant Cell Arteritis (GCA), Meningitis, Raised Intracranial Pressure (e.g., space-occupying lesion), Cerebral Venous Sinus Thrombosis (CVST), Idiopathic Intracranial Hypertension (IIH), Medication-overuse headache.

Thunderclap onset (maximal intensity <1 minute), New-onset headache in patients >50 or <10 years, Fever and neck stiffness, Papilloedema, Focal neurological deficits, Worsening with Valsalva/coughing, Postural component (worse when lying flat/standing), New headache in pregnancy or immunosuppression.

First-line imaging for acute 'worst ever' headache is non-contrast CT Head, ideally within 6 hours. If CT is negative and clinical suspicion remains, lumbar puncture (LP) is performed after 12 hours to look for bilirubin (xanthochromia). Inflammatory markers (ESR/CRP) are mandatory if Giant Cell Arteritis (GCA) is suspected. Magnetic Resonance Ischemi/Venography (MRI/MRV) is preferred for suspected cerebral venous sinus thrombosis. Routine bloods including FBC and U&Es help rule out infection or metabolic contributors. Management follows a stratified approach: simple analgesia/triptans for migraine, or emergent referral for neurosurgery in SAH.

The 'three questions' for migraine (disability, nausea, light sensitivity) are highly predictive. In suspected TCH, if the CT head is negative but performed within 6 hours of onset, a lumbar puncture may not be required per recent NICE/RCEM updates, although many centres still follow the 12-hour rule for xanthochromia. Always examine the optic discs; papilloedema is a cardinal sign of raised intracranial pressure. Medication-overuse headache (MOH) is common in patients using paracetamol or NSAIDs for >15 days/month or triptans/opioids for >10 days/month.

Aligns with the 'Acute Medicine' and 'Neurology' categories of the MLA Map. Emphasises the recognition of life-threatening 'secondary' headaches versus common 'primary' presentations. Understand the NICE (CG150) criteria for neuroimaging in headache and the management of GCA (high-dose steroids immediately).