What is the approach to writing a History of Present Illness (HPI) for a patient presenting with 2 days of nausea, vomiting, and headache?

Writing an HPI for Nausea, Vomiting, and Headache

Your HPI must systematically capture the specific clinical features that distinguish between life-threatening emergencies, primary headache disorders (especially migraine), cyclic vomiting syndrome, and common self-limited causes—this documentation directly determines whether the patient receives appropriate urgent intervention versus outpatient management.

Essential Opening Statement

Begin with the chief complaint, age, sex, and acute timeline: "This is a [age]-year-old [sex] presenting with 2 days of nausea, vomiting, and headache." 1, 2

Critical "Red Flag" Documentation (Document First)

You must explicitly document the presence or absence of these features to rule out life-threatening causes:

• Headache character: Ask specifically if this is the "worst headache of life" (subarachnoid hemorrhage occurs in 80% with this description) 2
• Neurological symptoms: Document any focal deficits, altered mental status, nuchal rigidity, brief loss of consciousness, or seizure activity 2
• Headache triggers: Note if worsened by Valsalva maneuver, coughing, sneezing, or exercise (suggests increased intracranial pressure) 1, 2
• Fever or infection signs: Document temperature and any signs of meningitis 1
• Progressive pattern: Ask if headaches are getting progressively worse over time 1
• Age consideration: New-onset headache in patient >50 years requires specific documentation 1

Characterize the Vomiting Pattern

Document these specific features to distinguish cyclic vomiting syndrome from other causes:

• Stereotypical pattern: Ask if patient has experienced similar episodes before, separated by symptom-free intervals of at least 1 week 3, 4, 2
• Episode frequency: Document if ≥3 discrete episodes in past year with 2 in prior 6 months 4, 2
• Episode duration: Note if episodes last <7 days 3, 4
• Prodromal symptoms: Ask about warning symptoms 1 hour before vomiting onset—sense of doom, panic, inability to communicate, fatigue, mental fog, restlessness, anxiety, diaphoresis, flushing, shakiness 3, 2
• Timing: Document if episodes typically occur in early morning hours 3
• Baseline health: Confirm patient is completely well between episodes 3, 4

Characterize the Headache

Document these features to assess for migraine:

• Duration: Note if headache lasts 4-72 hours when untreated 3, 2
• Location: Document if unilateral or bilateral 2
• Character: Ask if pulsating/throbbing 2
• Intensity: Rate severity and impact on function 1
• Associated symptoms: Specifically ask about photophobia, phonophobia, nausea, vomiting 3, 2
• Frequency: Document if headaches occur ≥15 days/month (chronic migraine threshold) 3, 1

Document Abdominal Pain

Explicitly note presence, location, and character of abdominal pain—this does NOT exclude cyclic vomiting syndrome (most CVS patients have abdominal pain during episodes). 3, 2

Medication and Substance History

Critical to document:

• Cannabis use: Ask specifically about duration and frequency (>1 year suggests cannabinoid hyperemesis syndrome rather than CVS) 2
• Recent medication changes: Document any new medications in past 2 weeks 5, 6
• Current medications: List all medications as potential contributors 5, 6
• Opioid or barbiturate use: Document to avoid in management 2

Associated Constitutional Symptoms

Document presence of: bowel urgency, acute diarrhea or constipation, feeling hot/cold, tremulousness 3, 2

Relevant Past Medical History

• Prior similar episodes: Number, frequency, and what resolved them 3, 2
• Family history of migraine: Especially important if onset at/around puberty 2
• Pregnancy status: Must document in women of childbearing age 5, 7
• Recent travel or food exposure: For acute gastroenteritis consideration 5, 8

Functional Impact

Document inability to work, attend social functions, perform routine activities, or ED visits related to symptoms 3

Common Documentation Pitfalls to Avoid

• Don't dismiss abdominal pain as excluding CVS—most CVS patients have this symptom 2
• Don't fail to ask about cannabis—this is the most common diagnostic error distinguishing CVS from cannabinoid hyperemesis 2
• Don't forget to document negative red flags explicitly—absence of concerning features must be stated, not implied 1, 2
• Don't use vague descriptors—quantify frequency (days/month), duration (hours), and intensity (0-10 scale) 3, 1