All EMS presentations
General MedicalClinical presentation

Nausea / vomiting

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

Clinical snapshot

Twenty-second review

  • Nausea and vomiting are generated by gastrointestinal, vestibular, metabolic, toxic, intracranial, cardiac, or pregnancy-related pathways and can cause dehydration and electrolyte loss.
  • Hematemesis, severe headache, peritonism, chest pain, shock, persistent bilious vomiting, or marked dehydration requires urgent assessment.
  • Keep vertigo or pregnancy in the differential; overlapping or concurrent illness remains possible.
  • For nausea / vomiting, 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
Bowel obstructionTime-sensitive high-risk possibility

HPI

Clarify duration and frequency; blood/coffee-ground material; bilious.

Signs & symptoms

Distension, focal neurology, severe headache, or cardiac features.

Focused exam

Perform a targeted cardiorespiratory, neurologic, abdominal, skin, and hydration assessment guided by the history; Assess function against baseline rather than relying on a single normal-looking measurement.

Brief pathophysiology

Bowel obstruction may cause nausea / vomiting through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Serious abdominal disease may initially have normal vitals. Tachycardia, tachypnea, fever or hypothermia, and falling pressure support systemic compromise but are not required.

Heart rate (bpm)

May rise

Pain, dehydration, inflammation, or shock can cause tachycardia.

Blood pressure (mmHg)

May fall

Hypotension suggests dehydration, hemorrhage, sepsis, or late disease.

Respiratory rate (breaths/min)

May rise

Tachypnea may reflect pain, acidosis, sepsis, or diaphragmatic irritation.

Temperature (°C)

High, normal, or low

Fever supports infection; normal temperature does not exclude a surgical abdomen.

Front-load in the triage report

  • Bowel obstruction: Distension, focal neurology, severe headache, or cardiac features.
  • Duration and frequency.
  • Blood/coffee-ground material?
Intracranial eventTime-sensitive high-risk possibility

HPI

Clarify blood/coffee-ground material; bilious; abdominal pain/distension.

Signs & symptoms

Distension, focal neurology, severe headache, or cardiac features.

Focused exam

Assess function against baseline rather than relying on a single normal-looking measurement; Assess hydration, abdomen, emesis character, neurologic status, gait, chest findings, and pregnancy possibility.

Brief pathophysiology

Intracranial event may cause nausea / vomiting through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Volume loss may first appear as tachycardia or postural symptoms; hypotension is a later sign. Fever or blood loss changes the likely cause and risk.

Heart rate (bpm)

May rise

Tachycardia may reflect volume depletion, fever, or distress.

Blood pressure (mmHg)

May fall

Relative or orthostatic change can precede resting hypotension.

Pulse pressure (mmHg)

May narrow

Reduced stroke volume can narrow pulse pressure as depletion worsens.

Temperature (°C)

Variable

Fever supports infection; hypothermia may occur in severe illness.

Front-load in the triage report

  • Intracranial event: Distension, focal neurology, severe headache, or cardiac features.
  • Blood/coffee-ground material?
  • Bilious?
Atypical ACSTime-sensitive high-risk possibility

HPI

Clarify bilious; abdominal pain/distension; diarrhea.

Signs & symptoms

Distension, focal neurology, severe headache, or cardiac features.

Focused exam

Assess function against baseline rather than relying on a single normal-looking measurement; Assess hydration, abdomen, emesis character, neurologic status, gait, chest findings, and pregnancy possibility.

Brief pathophysiology

Atypical ACS may cause nausea / vomiting through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Acute coronary syndrome frequently presents without a diagnostic vital-sign pattern. Abnormal observations suggest complications; normal observations do not exclude ischemia.

Blood pressure (mmHg)

High, normal, or low

Pain may elevate pressure; hypotension suggests major infarction or complication.

Heart rate (bpm)

High, normal, or low

Ischemia, conduction disturbance, medication, and autonomic response all affect rate.

Respiratory rate (breaths/min)

May rise

Tachypnea can reflect pain, heart failure, or shock.

Oxygen saturation (SpO₂)

Often preserved

Low SpO₂ suggests pulmonary edema or concurrent respiratory disease; normal does not exclude ACS.

Front-load in the triage report

  • Atypical ACS: Distension, focal neurology, severe headache, or cardiac features.
  • Bilious?
  • Abdominal pain/distension?
Common2 conditions
GastroenteritisCommon presentation pattern

HPI

Clarify duration and frequency; blood/coffee-ground material; bilious.

Signs & symptoms

Diarrhea, sick contacts, new medicines, or self-limited diffuse symptoms may support the cause.

Focused exam

Perform a targeted cardiorespiratory, neurologic, abdominal, skin, and hydration assessment guided by the history; Assess function against baseline rather than relying on a single normal-looking measurement.

Brief pathophysiology

Gastroenteritis 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

Volume loss may first appear as tachycardia or postural symptoms; hypotension is a later sign. Fever or blood loss changes the likely cause and risk.

Heart rate (bpm)

May rise

Tachycardia may reflect volume depletion, fever, or distress.

Blood pressure (mmHg)

May fall

Relative or orthostatic change can precede resting hypotension.

Pulse pressure (mmHg)

May narrow

Reduced stroke volume can narrow pulse pressure as depletion worsens.

Temperature (°C)

Variable

Fever supports infection; hypothermia may occur in severe illness.

Front-load in the triage report

  • Diarrhea, sick contacts, new medicines, or self-limited diffuse symptoms may support the cause.
  • Duration and frequency.
  • Blood/coffee-ground material?
Medication effectCommon presentation pattern

HPI

Clarify blood/coffee-ground material; bilious; abdominal pain/distension.

Signs & symptoms

Diarrhea, sick contacts, new medicines, or self-limited diffuse symptoms may support the cause.

Focused exam

Assess function against baseline rather than relying on a single normal-looking measurement; Assess hydration, abdomen, emesis character, neurologic status, gait, chest findings, and pregnancy possibility.

Brief pathophysiology

Medication effect 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

Volume loss may first appear as tachycardia or postural symptoms; hypotension is a later sign. Fever or blood loss changes the likely cause and risk.

Heart rate (bpm)

May rise

Tachycardia may reflect volume depletion, fever, or distress.

Blood pressure (mmHg)

May fall

Relative or orthostatic change can precede resting hypotension.

Pulse pressure (mmHg)

May narrow

Reduced stroke volume can narrow pulse pressure as depletion worsens.

Temperature (°C)

Variable

Fever supports infection; hypothermia may occur in severe illness.

Front-load in the triage report

  • Diarrhea, sick contacts, new medicines, or self-limited diffuse symptoms may support the cause.
  • Blood/coffee-ground material?
  • Bilious?
Mimics2 conditions
VertigoImportant alternative presentation

HPI

Clarify duration and frequency; blood/coffee-ground material; bilious.

Signs & symptoms

Motion-provoked symptoms or missed menses can redirect the assessment.

Focused exam

Perform a targeted cardiorespiratory, neurologic, abdominal, skin, and hydration assessment guided by the history; Assess function against baseline rather than relying on a single normal-looking measurement.

Brief pathophysiology

Vertigo can resemble nausea / vomiting through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Volume loss may first appear as tachycardia or postural symptoms; hypotension is a later sign. Fever or blood loss changes the likely cause and risk.

Heart rate (bpm)

May rise

Tachycardia may reflect volume depletion, fever, or distress.

Blood pressure (mmHg)

May fall

Relative or orthostatic change can precede resting hypotension.

Pulse pressure (mmHg)

May narrow

Reduced stroke volume can narrow pulse pressure as depletion worsens.

Temperature (°C)

Variable

Fever supports infection; hypothermia may occur in severe illness.

Front-load in the triage report

  • Motion-provoked symptoms or missed menses can redirect the assessment.
  • Duration and frequency.
  • Blood/coffee-ground material?
PregnancyImportant alternative presentation

HPI

Clarify blood/coffee-ground material; bilious; abdominal pain/distension.

Signs & symptoms

Motion-provoked symptoms or missed menses can redirect the assessment.

Focused exam

Assess function against baseline rather than relying on a single normal-looking measurement; Assess hydration, abdomen, emesis character, neurologic status, gait, chest findings, and pregnancy possibility.

Brief pathophysiology

Pregnancy can resemble nausea / vomiting through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Volume loss may first appear as tachycardia or postural symptoms; hypotension is a later sign. Fever or blood loss changes the likely cause and risk.

Heart rate (bpm)

May rise

Tachycardia may reflect volume depletion, fever, or distress.

Blood pressure (mmHg)

May fall

Relative or orthostatic change can precede resting hypotension.

Pulse pressure (mmHg)

May narrow

Reduced stroke volume can narrow pulse pressure as depletion worsens.

Temperature (°C)

Variable

Fever supports infection; hypothermia may occur in severe illness.

Front-load in the triage report

  • Motion-provoked symptoms or missed menses can redirect the assessment.
  • Blood/coffee-ground material?
  • Bilious?
Red flags

Findings that should escalate concern

  • Hematemesis, severe headache, peritonism, chest pain, shock, persistent bilious vomiting, or marked dehydration requires urgent assessment.
  • Bowel obstruction, intracranial event, or atypical ACS: Distension, focal neurology, severe headache, or cardiac features.
Related EMS presentations

Continue the clinical pathway

GIAbdominal painNeurologicDizziness / vertigoGIDiarrheaGIGI bleedEndocrine/MetabolicHyperglycemia / possible DKA-HHSObstetric/GynecologicPregnancy / labour
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. E07: Nausea and VomitingBC Emergency Health Services Handbook

    Official BCEHS clinical practice guidance for nausea and vomiting.

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. Efficacy and Safety of Pharmacologic Therapies for Nausea and Emesis in the Emergency DepartmentAnnals of Emergency Medicine · 2025

    Systematic review of emergency-department antiemetic evidence and symptom management.