Clerking headache (acute) in adults

Headache is pain on any part of the head, behind the eyes or ears, or in the upper neck. Headaches represent less than a tenth of all emergency room visits. More than 90 percent of people suffer a headache at least once a year – women slightly more often than men.

Diagnosis is usually achieved primarily from history. Hallmark physical signs are often absent, and many physical findings are non-specific. The majority of patients presenting with acute headache have a benign diagnosis, but a high index of suspicion should still be maintained for life-threatening causes of headache.


  • Acute sinusitis

Hx: frontal headache, nasal congestion, mucopurulent nasal discharge, fever; headache aggravated by bending forwards, coughing, or sneezing

PE: sinus tenderness, reproducible pain on percussion of frontal and maxillary sinuses strongly indicates acute bacterial sinusitis

Inv: no investigation

  • Otitis media

Hx: common in children; presents with otalgia, irritability, decreased hearing, anorexia, vomiting, or fever, usually in the presence of an ongoing viral respiratory infection

PE: bulging, opacified tympanic membrane with decreased mobility; membrane may be white, yellow, pink, or red; diagnosis is generally made with conventional otoscopy

Inv: no investigation

  • Menstrual headache

Hx: episodic headache, monthly/cyclical occurrence (around time of menses)

PE: usually normal

  • Medication withdrawal

Hx: recent medication changes, usually hypertension medication or antihistamines, caffeine, pseudoephedrine, opiates, corticosteroids

PE: usually normal

Inv: no investigation

  • Medication overuse

Hx: hx of taking large amounts of over-the-counter analgesics

PE: usually normal

Inv: no investigation

  • Cervical paraspinal muscle tenderness

Hx: tight and band-like or vice-like headache, bilateral, steady, aching, non-pulsatile, constricting pain (not severe)

PE: muscle tenderness on palpation, may be impaired movement of cervical spine

Inv: no investigation

  • Migraine

Hx: unilateral, pulsing, or throbbing pain, migraine with aura: nausea, vomiting, visual phenomenon (flashing lights, zig-zag lines), photophobia, phonophobia, may have transient focal neurological deficits; aura symptoms last <60 minutes;

a helpful mnemonic is POUNDing: Pulsatile quality, duration of 4 to 72 hours, Unilateral location, Nausea or vomiting, and Disabling intensity (score of 5: migraine is likely; 3-4: migraine is possible; 1-2: migraine is unlikely)

PE: if migraine with aura, may see focal neurological deficit on examination, otherwise examination normal

Inv: no investigation

  • Tension headache

Hx: often associated with emotional stressors, depression, insomnia; headache may be described as tight and band-like or vice-like, bilateral, steady, aching, non-pulsatile, constricting pain (not severe)

PE: pericranial tenderness is common, otherwise examination may be normal

Inv: no investigation

  • Dental caries/wisdom tooth impaction

Hx: pain on drinking or eating sweet, hot, or cold foods or fluids; wisdom tooth pain has characteristic ‘horseshoe’ distribution with intense, throbbing, unilateral pain; seen in young adults

PE: dental caries visible, enamel soft on probing, dental abscess may cause breath odour, enlarged cervical nodes, fever, and swollen jaw

Inv: no investigation

  • Temporomandibular joint syndrome

Hx: typically presents with 3 characteristic features: temporomandibular joint pain on mastication, noise in the joint, and limited mandibular movement with jaw locking

PE: tenderness at TMJ, limited mandibular movement, TMJ click

Inv: no investigation

  • Stroke

Hx: neurological deficit, headache, nausea, vomiting, vertigo, altered mental status

PE: neurological deficit

Inv: CT brain without contrast : hyperattenuating lesion in haemorrhagic stroke; hypoattenuating (dark) lesion in ischaemic stroke, although may not show up within the first 24-48 hours of ischaemic stroke

  • Meningitis

Hx: higher likelihood in HIV or immunocompromised, classic triad present in two-thirds of patients of fever, headache, stiff neck; [3] other symptoms are nausea, vomiting, seizures, focal deficits, photophobia, rash

PE: meningeal signs: 5% have Brudzinski’s sign (hip flexion with neck flexion), 5% have Kernig’s sign (painful knee extension with hip flexed), may see papilloedema with increased ICP

Inv: CT brain without contrast: negative

  • Brain abscess

Hx: headache, fever, focal neurological deficit, may be immunocompromised

PE: papilloedema

Inv: CT brain with contrast: rings of enhancement surrounding low-density centre and surrounded by white matter oedema

  • Acute hydrocephalus

Hx: sudden severe headache, vomiting, lethargy

PE: may be normal

Inv: CT brain without contrast : enlarged ventricles

  • Benign intracranial hypertension (pseudotumour cerebri)

Hx: typically female, obese, age 20 to 30 years; nausea, vomiting, headaches, transient visual disturbances, some association with medication use (cimetidine, corticosteroids, danazol, isotretinoin, levothyroxine, lithium, minocycline, nalidixic acid, nitrofurantoin, tamoxifen, tetracycline, or trimethoprim-sulfamethoxazole)

PE: papilloedema

Inv: no investigation

  • Brain tumour

Hx: may present with unexplained weight loss, focal neurological deficits; hx of cancer; headache that awakens patient from sleep or is present upon awakening, decreases after being awake for several hours, is aggravated by exertion or Valsalva

PE: focal neurological deficits

Inv: CT brain with or without contrast: ring-enhancing lesions with or without surrounding oedema

  • Hypertensive encephalopathy

Hx: acute-onset headache, nausea, vomiting, may have altered mental status or visual disturbance

PE: elevated BP, mean arterial pressure >150 to 200 mmHg

Inv: CT brain: negative (to rule out bleeding and other pathologies)

  • Eclampsia/pre-eclampsia

Hx: third trimester pregnancy or peripartum, pedal oedema, increase weight gain (>5 lb/week); seizures distinguish eclampsia

PE: BP >140/90 mmHg

Inv: CT brain: negative

  • Pituitary apoplexy

Hx: headache, nausea, vomiting, altered mental status, 2:1 male predominance, most commonly seen in ages 37 to 57 years

PE: visual deficits: diplopia, ptosis, changes in visual field

Inv: MRI brain: pituitary haemorrhage

  • Venous sinus thrombosis

Hx: headache, nausea, vomiting, seizures, hypercoagulable states

PE: papilloedema, visual field deficits, cranial nerve palsies, focal neurological deficits

Inv: CT brain: delta sign (dense triangle from hyperdense thrombus) within the superior sagittal sinus

  • Epidural haematoma

Hx: blunt trauma to temporoparietal aspect of skull, classic presentation of loss of consciousness followed by period of lucidity and subsequent neurological deterioration; may have headache, vomiting, lethargy

PE: physical examination may be normal, depending upon location, size, and presence or absence of mass effect, ipsilateral pupillary dilatation seen in 30% of cases

Inv: CT brain without contrast: lenticular/biconvex hyperdensity

  • Subarachnoid haemorrhage

Hx: 1% of all patients who present to the emergency department with headaches have SAH; may present with a ‘thunderclap’ headache (sudden onset of severe headache, seen in 12%), or may have a ‘sentinel’ headache (mild headache preceding the severe one, seen in <10%); usually seen in women aged 40 to 60 years

PE: nuchal rigidity seen in 70%

Inv: CT brain without contrast: blood in the area of the circle of Willis

  • Subdural haematoma

Hx: more likely with hx of alcohol abuse, anticoagulants, frequent falls, seizure disorder; may present with altered mental status, seizures, coma

PE: may be normal, depending upon location, size, and presence or absence of mass effect, or patients may have altered mental status, focal deficits, seizures, pupillary abnormalities, or coma

Inv: CT brain without contrast: half-moon or crescent-shaped clot overlying the hemispheric convexity

  • Carbon monoxide poisoning

Hx: non-specific early signs and symptoms; may be exposure to furnace (in old house), space heaters, house fires, car exhaust, or gas stoves; flu-like symptoms, other household members with similar symptoms or recently deceased pets, morning headaches, dizziness, ataxia, confusion, nausea/vomiting, may present in late autumn/early winter

PE: poor co-ordination, memory loss, wheeze, hyperventilation

Inv: carboxyhaemoglobin level: >3% non-smokers; >10% smokers

  • Head trauma

Hx: hx of recent head trauma, possible loss of consciousness

PE: physical examination may be normal or may reveal evidence of trauma, scalp laceration, contusion

Inv: no investigation

  • Acute mountain sickness/hypoxia

Hx: symptoms include headache, anorexia, nausea, vomiting, lightheadedness, fatigue, dizziness, and sleep disturbance; headache tends to be diffuse and constant, often worsening with straining, lifting, or coughing

PE: mental state changes, papilloedema, retinal haemorrhages

Inv: no investigation

  • Cluster headaches

Hx: more often in men >20 years, severe, unilateral orbital, supra-orbital, or temporal pain lasting 15 to 180 minutes, reddened eyes, excessive lacrimation, nasal congestion, facial swelling

PE: conjunctival injection, lacrimation, facial swelling, miosis, ptosis, rhinorrhoea

Inv: no investigation

  • Trigeminal neuralgia

Hx: paroxysms of severe unilateral pain in the trigeminal nerve distribution lasting seconds, no pain between paroxysms, may be hx of herpetic episode or multiple sclerosis

Inv: no investigation

  • Acute angle-closure glaucoma

Hx: acute, unilateral eye and/or forehead pain, blurred vision, halos around lights, injected sclera, nausea/vomiting, age >50 years

PE: mid-dilated pupils, decreased visual acuity, increased intra-ocular pressure, diagnosis is made by noting characteristic changes in the optic nerve head, with or without visual field loss

Inv: tonometry: >21 mmHg suspicious; >24 mmHg abnormal

  • Giant cell arteritis

Hx: age >50, female predominance, may have hx of polymyalgia rheumatica, may present with painless monocular vision loss, flu-like symptoms, jaw claudication

PE: unilateral blindness, tenderness to temporal area, funduscopic examination may show optic nerve oedema

Inv: ESR: >50 mm/hour

  • Zika virus infection

Hx: recent travel to or residence in an endemic area; many patients are asymptomatic, any symptoms are mild and last for several days to a week; common features are acute onset of fever with arthralgia, conjunctivitis, myalgia, and headache

PE: non-specific clinical findings, resembling viral or flu-like illness, maculopapular rash


  • reverse transcription-polymerase chain reaction (RT-PCR) on blood or urine: positive for viral RNA
  • ELISA: positive for virus-specific antibodies