All EMS presentations
NeurologicClinical presentation

Headache

A streamlined, differential-led presentation for rapid clinical review.

Clinical snapshot

Twenty-second review

  • Headache results from pain-sensitive intracranial, vascular, meningeal, ocular, sinus, or musculoskeletal structures; primary headache is common but dangerous secondary causes must be screened.
  • Thunderclap onset, focal deficit, meningism, pregnancy or postpartum state, anticoagulation, trauma, seizure, or declining GCS is time-sensitive.
  • Keep glaucoma or carbon monoxide exposure in the differential; overlapping or concurrent illness remains possible.
  • For headache, trends and combinations of findings are more informative than one isolated vital sign.
Differentials

Compare the clinical patterns

The repeated material is grouped inside each possibility. Open only the condition you need.

Serious3 conditions
Subarachnoid hemorrhageTime-sensitive high-risk possibility

HPI

Clarify sudden or gradual; thunderclap/maximal at onset; first/worst or different.

Signs & symptoms

Sudden onset, neurologic change, fever, meningism, or organ injury.

Focused exam

Record GCS components, pupils, speech, gaze, motor symmetry, sensation, coordination, and gait when safe; Compare findings with baseline and collateral history.

Brief pathophysiology

Subarachnoid hemorrhage may cause headache through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Hemorrhage is a trend diagnosis: tachycardia and narrowing pulse pressure may precede hypotension. Age, pregnancy, medications, and pacing can blunt expected responses.

Heart rate (bpm)

Often rises

Tachycardia is a common compensatory response but may be absent.

Pulse pressure (mmHg)

May narrow

Narrowing pulse pressure can reflect reduced stroke volume.

Blood pressure (mmHg)

May fall late

A normal pressure does not exclude significant compensated hemorrhage.

MAP (mmHg)

May fall

A falling trend supports worsening perfusion; interpret with mental status and skin signs.

Front-load in the triage report

  • Subarachnoid hemorrhage: Sudden onset, neurologic change, fever, meningism, or organ injury.
  • Sudden or gradual?
  • Thunderclap/maximal at onset?
MeningitisTime-sensitive high-risk possibility

HPI

Clarify thunderclap/maximal at onset; first/worst or different; exact onset.

Signs & symptoms

Sudden onset, neurologic change, fever, meningism, or organ injury.

Focused exam

Compare findings with baseline and collateral history; Assess onset, neurologic status, pupils and vision, neck stiffness, rash, BP context, trauma, and pregnancy status.

Brief pathophysiology

Meningitis may cause headache through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

CNS infection may produce fever and systemic illness, but classic findings and abnormal vitals can be absent. Altered mental status, rash, shock, or seizures increase urgency.

Temperature (°C)

Often elevated

Fever supports infection; normal temperature does not exclude it.

Heart rate (bpm)

May rise

Tachycardia may reflect fever, pain, or sepsis.

Blood pressure (mmHg)

May fall with sepsis

Hypotension suggests systemic involvement or shock.

Blood glucose (mmol/L)

Check early

Glucose disturbance is an important reversible mimic of altered mentation or seizure.

Front-load in the triage report

  • Meningitis: Sudden onset, neurologic change, fever, meningism, or organ injury.
  • Thunderclap/maximal at onset?
  • First/worst or different?
Hypertensive emergencyTime-sensitive high-risk possibility

HPI

Clarify first/worst or different; exact onset; neurologic deficit.

Signs & symptoms

Sudden onset, neurologic change, fever, meningism, or organ injury.

Focused exam

Compare findings with baseline and collateral history; Assess onset, neurologic status, pupils and vision, neck stiffness, rash, BP context, trauma, and pregnancy status.

Brief pathophysiology

Hypertensive emergency may cause headache through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

A markedly elevated pressure becomes a hypertensive emergency when accompanied by acute target-organ injury. Treat the patient and trajectory, not an isolated number.

Blood pressure (mmHg)

Markedly elevated

Repeat with correct cuff size and assess for acute neurologic, cardiac, renal, or vascular injury.

MAP (mmHg)

Elevated

MAP rises with severe hypertension but does not establish target-organ injury.

Heart rate (bpm)

Variable

Heart rate depends on cause, medication, pain, and autonomic response.

Oxygen saturation (SpO₂)

Usually preserved

Low SpO₂ may indicate acute pulmonary edema or another concurrent emergency.

Front-load in the triage report

  • Hypertensive emergency: Sudden onset, neurologic change, fever, meningism, or organ injury.
  • First/worst or different?
  • Exact onset.
Common2 conditions
MigraineCommon presentation pattern

HPI

Clarify sudden or gradual; thunderclap/maximal at onset; first/worst or different.

Signs & symptoms

Prior similar pattern, gradual onset, photophobia, nausea, or muscular tenderness may support it.

Focused exam

Record GCS components, pupils, speech, gaze, motor symmetry, sensation, coordination, and gait when safe; Compare findings with baseline and collateral history.

Brief pathophysiology

Migraine may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

Neurologic differentials often have nonspecific vital signs. Glucose, pressure, oxygenation, and cardiac rate/rhythm help identify mimics and prevent secondary injury.

Blood glucose (mmol/L)

Check early

Hypoglycemia can mimic or worsen neurologic dysfunction.

Blood pressure (mmHg)

Trend pressure

Both hypo- and hypertension can be clinically important in neurologic disease.

Oxygen saturation (SpO₂)

Prevent hypoxemia

Low saturation can worsen brain injury or suggest an alternate cause.

Heart rate (bpm)

Assess rate / rhythm

Rhythm disturbance can cause cerebral hypoperfusion or embolic events.

Front-load in the triage report

  • Prior similar pattern, gradual onset, photophobia, nausea, or muscular tenderness may support it.
  • Sudden or gradual?
  • Thunderclap/maximal at onset?
Tension headacheCommon presentation pattern

HPI

Clarify thunderclap/maximal at onset; first/worst or different; exact onset.

Signs & symptoms

Prior similar pattern, gradual onset, photophobia, nausea, or muscular tenderness may support it.

Focused exam

Compare findings with baseline and collateral history; Assess onset, neurologic status, pupils and vision, neck stiffness, rash, BP context, trauma, and pregnancy status.

Brief pathophysiology

Tension headache may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

Neurologic differentials often have nonspecific vital signs. Glucose, pressure, oxygenation, and cardiac rate/rhythm help identify mimics and prevent secondary injury.

Blood glucose (mmol/L)

Check early

Hypoglycemia can mimic or worsen neurologic dysfunction.

Blood pressure (mmHg)

Trend pressure

Both hypo- and hypertension can be clinically important in neurologic disease.

Oxygen saturation (SpO₂)

Prevent hypoxemia

Low saturation can worsen brain injury or suggest an alternate cause.

Heart rate (bpm)

Assess rate / rhythm

Rhythm disturbance can cause cerebral hypoperfusion or embolic events.

Front-load in the triage report

  • Prior similar pattern, gradual onset, photophobia, nausea, or muscular tenderness may support it.
  • Thunderclap/maximal at onset?
  • First/worst or different?
Mimics2 conditions
GlaucomaImportant alternative presentation

HPI

Clarify sudden or gradual; thunderclap/maximal at onset; first/worst or different.

Signs & symptoms

Eye findings or clustered environmental symptoms can redirect assessment.

Focused exam

Record GCS components, pupils, speech, gaze, motor symmetry, sensation, coordination, and gait when safe; Compare findings with baseline and collateral history.

Brief pathophysiology

Glaucoma can resemble headache through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Neurologic differentials often have nonspecific vital signs. Glucose, pressure, oxygenation, and cardiac rate/rhythm help identify mimics and prevent secondary injury.

Blood glucose (mmol/L)

Check early

Hypoglycemia can mimic or worsen neurologic dysfunction.

Blood pressure (mmHg)

Trend pressure

Both hypo- and hypertension can be clinically important in neurologic disease.

Oxygen saturation (SpO₂)

Prevent hypoxemia

Low saturation can worsen brain injury or suggest an alternate cause.

Heart rate (bpm)

Assess rate / rhythm

Rhythm disturbance can cause cerebral hypoperfusion or embolic events.

Front-load in the triage report

  • Eye findings or clustered environmental symptoms can redirect assessment.
  • Sudden or gradual?
  • Thunderclap/maximal at onset?
Carbon monoxide exposureImportant alternative presentation

HPI

Clarify thunderclap/maximal at onset; first/worst or different; exact onset.

Signs & symptoms

Eye findings or clustered environmental symptoms can redirect assessment.

Focused exam

Compare findings with baseline and collateral history; Assess onset, neurologic status, pupils and vision, neck stiffness, rash, BP context, trauma, and pregnancy status.

Brief pathophysiology

Carbon monoxide exposure can resemble headache through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Standard pulse oximetry can appear normal in carbon-monoxide poisoning. Exposure history, neurologic findings, ECG, and definitive co-oximetry matter more than the displayed SpO₂.

Oxygen saturation (SpO₂)

May appear normal

Standard SpO₂ cannot distinguish oxyhemoglobin from carboxyhemoglobin.

Heart rate (bpm)

May rise

Tachycardia can reflect tissue hypoxia or physiologic stress.

Respiratory rate (breaths/min)

May rise

Tachypnea may occur, but a normal rate does not exclude toxicity.

Blood pressure (mmHg)

Variable

Pressure may be preserved; hypotension suggests severe poisoning or another injury.

Front-load in the triage report

  • Eye findings or clustered environmental symptoms can redirect assessment.
  • Thunderclap/maximal at onset?
  • First/worst or different?
Red flags

Findings that should escalate concern

  • Thunderclap onset, focal deficit, meningism, pregnancy or postpartum state, anticoagulation, trauma, seizure, or declining GCS is time-sensitive.
  • Subarachnoid hemorrhage, meningitis, or hypertensive emergency: Sudden onset, neurologic change, fever, meningism, or organ injury.
Related EMS presentations

Continue the clinical pathway

NeurologicStroke / TIANeurologicSeizureTraumaHead injuryNeurologicAcute visual complaintEnvironmentalCarbon monoxide exposure
References

Clinical and academic sources

Curated clinical guidance and peer-reviewed evidence supporting this presentation. Current BCEHS guidance, medical direction, and local policy remain authoritative for practice.

BCEHS Handbook — specific CPGs

  1. F04: HeadacheBC Emergency Health Services Handbook

    Official BCEHS clinical practice guidance for headache.

Supporting clinical and academic evidence

  1. CEDIS Presenting Complaint List updateCanadian Association of Emergency Physicians

    Presenting-complaint terminology and categorization context. It does not establish a prehospital “top 100” ranking.

  2. WHO Medical Emergency ChecklistWorld Health Organization

    A structured emergency assessment framework intended to reduce missed life-threatening conditions.

  3. Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients With Acute HeadacheAnnals of Emergency Medicine · 2019

    Red flags, subarachnoid hemorrhage evaluation, and risk-based assessment of acute headache.