Diagnostic Approach to Nausea, Vomiting, and Epigastric Pain

Immediate Life-Threatening Causes to Exclude First

The American Heart Association recommends obtaining an ECG within 10 minutes to exclude myocardial infarction, which presents atypically with epigastric pain in patients with diabetes or vascular risk factors, with mortality rates of 10-20% if missed 2, 3
The American College of Cardiology recommends measuring serial cardiac troponins at 0 and 6 hours to definitively rule out acute coronary syndrome 3
The Society of Critical Care Medicine recommends checking vital signs immediately for tachycardia ≥110 bpm, fever ≥38°C, or hypotension, which predict perforation or sepsis with high specificity 2, 4
The American Gastroenterological Association recommends performing a physical examination looking specifically for peritoneal signs (rigidity, rebound tenderness, absent bowel sounds) suggesting perforated peptic ulcer, which has 30% mortality if treatment is delayed 2, 3

The British Society of Gastroenterology states that gastroparesis characteristically presents with nausea, vomiting, and epigastric pain, affecting an estimated 4% of the population 5, 6
The American Gastroenterological Association recommends solid meal gastric scintigraphy performed for 4 hours as the gold standard for diagnosis of gastroparesis 6
The National Institute of Diabetes and Digestive and Kidney Diseases states that common etiologies of gastroparesis include diabetes (25%), post-surgical, medications (opioids, GLP-1 agonists), and idiopathic (largest category) 5, 6
The American College of Gastroenterology recommends that peptic ulcer disease has an incidence of 0.1-0.3%, with complications occurring in 2-10% of cases, presenting with epigastric pain not relieved by antacids 2, 3

The American Gastroenterological Association recommends ordering a complete blood count to check for anemia (alarm feature requiring urgent endoscopy) 1, 2
The Society of Critical Care Medicine recommends checking C-reactive protein and serum lactate to exclude serious organic pathology 2, 4
The National Institute of Diabetes and Digestive and Kidney Diseases states that liver and renal function tests should be ordered 2, 4
The American College of Gastroenterology recommends checking serum amylase or lipase (≥2x normal for lipase, ≥4x normal for amylase) to exclude acute pancreatitis, which has 80-90% sensitivity and specificity 2, 4

The American College of Gastroenterology recommends starting empirical therapy immediately with high-dose PPI therapy: omeprazole 20-40 mg once daily before meals for suspected acid-related pathology, with healing rates of 80-90% for duodenal ulcers and 70-80% for gastric ulcers 2, 4, 3
The Society of Critical Care Medicine recommends providing IV access and fluid resuscitation if hemodynamically unstable 3

The British Society of Gastroenterology recommends that age ≥55 years with persistent symptoms warrants non-urgent endoscopy 1, 4
The American College of Gastroenterology states that persistent vomiting is an alarm feature that mandates investigation regardless of age 1, 2

The American Heart Association recommends never dismissing cardiac causes in patients with "atypical" epigastric pain regardless of age—obtain ECG and serial troponins at 0 and 6 hours 2, 3
The Rome Foundation states that do not attribute persistent vomiting to functional dyspepsia—Rome IV criteria state this suggests another disorder and mandates investigation for structural disease 1, 2, 4