Headache in the ED — Approach & Revision

Settle them, and check the basics

all at once, calmly

Red flags — what each should make you think

Thunderclap: maximal in minutessubarachnoid haemorrhage Fever, neck stiffness, rashmeningitis / encephalitis Worse lying/coughing, vomitingraised intracranial pressure Age >50, scalp/jaw/visual symptomsgiant cell arteritis Pregnant/postpartum + high BPpre-eclampsia or CVST Focal neurology or reduced GCSa structural cause — image

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Pearl

The one question that sorts most serious headaches: how fast did it peak? A headache at maximum intensity within seconds to minutes is a thunderclap — CT-and-worry until proven otherwise, however well they look now.

Your first moves — all at once, calmly

A–EAssess A–E, full obsinclude BP and temperature
GCSNeuro checkGCS, pupils, focal deficit, neck stiffness, fundoscopy
gluBlood glucosea quick, reversible cause not to miss
✚BloodsFBC, CRP, ESR if GCA suspected, U&E, coag; cultures if febrile
℞Don't delay treatment if meningitis suspectedantibiotics before imaging if it holds things up
CTConsider CT head, then LP if indicatedimage first if focal signs or reduced GCS

Understand the headache & the person

onset routes you

Take a focused history — the onset routes you

Thunderclap (peak in minutes) — SAH, venous sinus thrombosis, dissection
Fever + meningism — meningitis, encephalitis
Progressive, worse waking/coughing/lying, vomiting — raised ICP
Age >50, temporal/jaw/visual — giant cell arteritis
Pregnant/postpartum + high BP — pre-eclampsia or CVST

Background that shifts the odds: pregnancy status, immunosuppression or cancer, anticoagulation, prothrombotic risk, and whether this is different from their usual headaches.

Work A–E — assess and act as you go

Here the examination is mostly neurological, but the ABCs still come first.

AAirway. A reduced GCS threatens the airway.protect the airway, escalate early if GCS dropping

BBreathing. Abnormal breathing patterns can signal a brainstem or ICP problem.oxygen, monitor, escalate

CCirculation. A very high BP with symptoms → hypertensive emergency; in pregnancy → pre-eclampsia.measure BP properly, obstetric call if pregnant

DDisability. GCS, pupils, focal deficit, neck stiffness, fundoscopy for papilloedema, photophobia. Check glucose.focal signs or papilloedema → image before any LP

EExposure. A non-blanching rash (meningococcal) and temperature.if meningococcal suspected, treat immediately

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Pearl

Never let imaging delay antibiotics in suspected meningitis. If a CT is needed first, give the antibiotics before the scan — minutes matter, and treatment doesn't wait for the LP.

Rule out the killers

tap to open each

Each card gives you what points toward it, what would rule it in, what lets you stand it down, and how to manage it.

points toward it

Sudden "worst headache of my life", maximal at onset, often with vomiting, neck stiffness, or a brief loss of consciousness.

rule in

CT head — highly sensitive within 6 hours of onset. If CT normal but presented later, an LP at ≥12 hours looks for xanthochromia.

manage it

Urgent neurosurgery/stroke referral, blood pressure control, nimodipine, analgesia and antiemetics.

Source: CT head · LP for xanthochromia

points toward it

Fever, headache, neck stiffness, photophobia, a non-blanching rash, altered mental state, or seizures (encephalitis).

rule in

Lumbar puncture (after CT if there are focal signs, reduced GCS, or immunocompromise).

manage it

Don't delay. IV ceftriaxone (add amoxicillin if listeria risk), IV aciclovir if encephalitis suspected, dexamethasone. In the community with suspected meningococcal disease, give benzylpenicillin before transfer.

Source: NICE NG240 — meningitis & meningococcal disease

points toward it

Headache that's progressive, worse on waking, coughing or lying flat, with vomiting, focal signs or papilloedema.

rule in

CT or MRI head showing a mass, bleed or hydrocephalus.

manage it

Neurosurgical referral. Avoid LP if raised ICP is suspected.

Source: CT / MRI · neurosurgery

points toward it

Age over 50, temporal headache, scalp tenderness, jaw claudication, and visual disturbance.

rule in

Raised ESR/CRP, supported by temporal artery ultrasound or biopsy.

manage it

Start high-dose steroids urgently — don't wait for the biopsy — to protect sight. Urgent ophthalmology and rheumatology.

Source: ESR/CRP · BSR — giant cell arteritis

points toward it

Subacute or thunderclap headache in pregnancy/postpartum or a prothrombotic state, with seizures, focal signs or papilloedema.

rule in

CT venogram or MR venogram.

manage it

Anticoagulation, with neurology involvement.

Source: CT/MR venogram · neurology

points toward it

Pregnant beyond 20 weeks (or recently postpartum) with headache, high blood pressure and proteinuria, ± visual symptoms or epigastric pain.

rule in

Raised BP + proteinuria in pregnancy; end-organ features on bloods/exam.

manage it

Obstetric emergency — controlled BP lowering and magnesium sulfate for seizure prophylaxis/eclampsia. Urgent obstetrics.

Source: NICE NG133 — hypertension in pregnancy

Then the common, benign causes

Once the red flags are excluded: migraine, tension-type headache, medication-overuse headache and sinusitis. Diagnose these by pattern after the dangerous causes are cleared.

Investigate — what to order, when, and what it tells you

test with a question in mind

CT head

When

Thunderclap onset, focal signs, reduced GCS, or features of raised ICP.

Tells you

Bleed (including SAH), mass, or hydrocephalus. Most sensitive for SAH within 6 hours.

Trap

A normal CT does not fully exclude SAH later after onset — that's where the LP comes in.

Lumbar puncture

When

After CT: for SAH (xanthochromia, timed ≥12 hours from onset) or to diagnose meningitis.

Tells you

Xanthochromia (SAH); cell count, protein, glucose and cultures (meningitis).

Trap

Avoid if raised ICP is suspected — image and assess first.

Bloods

ESR / CRP

Raised in GCA — check when the story fits.

Cultures / glucose / coag

Sepsis screen if febrile; glucose as a reversible cause; coag if bleeding/anticoagulated.

Blood pressure & βhCG

Blood pressure

The key vital in pre-eclampsia and hypertensive emergency.

βhCG

Check if pregnancy is possible.

How the plan comes together

disposition · handover

You've separated the dangerous from the benign, imaged where needed, and treated what couldn't wait. Now: where do they go?

discharge

Red flags excluded, a benign pattern (migraine, tension-type), normal exam, settling with treatment.

Safety-net: clear return advice (especially thunderclap or new neurology), GP follow-up.

refer / admit

Any red flag, abnormal imaging, or an unresolved diagnosis → the relevant specialty (neurosurgery, stroke, neurology, ophthalmology, obstetrics).

Hand over: onset speed, red flags, imaging and treatment given, what would change the plan.

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Pearl

Your handover is part of the plan. "Headache, this onset story, these red flags present or absent, CT showed X, treated with Y, my worry is Z" is the line that keeps them safe. Nicely done getting here.