What is the difference between hematemesis (vomiting blood) and hemoptysis (coughing up blood)?

Distinguishing Hematemesis from Hemoptysis

Hemoptysis is the expectoration of blood from the lower respiratory tract (lungs or bronchial tubes), while hematemesis is the vomiting of blood from the gastrointestinal tract—these conditions must be differentiated immediately as they have entirely different etiologies, diagnostic approaches, and management strategies. 1

Key Clinical Distinctions

Source and Mechanism

• Hemoptysis originates from the tracheobronchial tree and is coughed up, typically from bronchial arteries under systemic pressure 1, 2
• Hematemesis originates from the esophagus, stomach, or upper gastrointestinal tract and is vomited up 3

Appearance and Characteristics of Blood

Hemoptysis typically presents with:

• Bright red, frothy blood mixed with air bubbles (due to mixing with air in the respiratory tract) 1
• Blood that is alkaline in pH 4
• Blood mixed with sputum or mucus 5
• Preceded by a sensation of gurgling or tickling in the chest or throat 4

Hematemesis typically presents with:

• Dark red or "coffee-ground" appearance (due to gastric acid exposure) 3
• Blood that is acidic in pH 4
• Blood mixed with food particles or gastric contents 3
• Associated with nausea or epigastric discomfort 4

Critical Diagnostic Pitfalls to Avoid

Pseudohemoptysis

• Blood originating from nasopharyngeal sources can mimic hemoptysis and must be excluded through careful examination 1, 4
• Up to 15% of patients presenting with apparent rectal bleeding actually have upper GI bleeding, highlighting the importance of confirming the true source 3

Immediate Assessment Priorities

• Determine hemodynamic stability first: Assess for orthostatic hypotension, tachycardia, or hemoglobin drop ≥1.5 g/dL, which require ICU admission regardless of source 5, 3
• Quantify severity: Massive hemoptysis (>100-200 mL/24 hours or causing airway compromise) requires urgent bronchoscopy for airway protection, as asphyxiation risk supersedes the absolute volume of blood 5, 6

Associated Clinical Features

Hemoptysis is commonly associated with:

• Respiratory symptoms: cough, dyspnea, chest pain 1
• Common etiologies: bronchiectasis, respiratory infections, lung cancer, tuberculosis, chronic obstructive pulmonary disease 6, 1
• In young adults: aspiration pneumonitis, pulmonary contusion, acute respiratory infections 6

Hematemesis is commonly associated with:

• Gastrointestinal symptoms: abdominal pain, melena, signs of liver disease 3
• Common etiologies: peptic ulcer disease, esophageal varices, gastritis, Mallory-Weiss tears 3

Initial Diagnostic Approach

For suspected hemoptysis:

• Chest radiography is the appropriate initial imaging modality 6, 1
• CT chest with IV contrast should follow if hemoptysis is significant, chest X-ray is abnormal, or etiology remains unclear 6, 2
• Bronchoscopy is indicated for massive hemoptysis requiring airway clearance or when malignancy is suspected 6, 2

For suspected hematemesis:

• Upper endoscopy is required to exclude an upper GI source, as this can definitively identify the bleeding site 3
• Complete blood count, coagulation studies, liver function tests should be obtained 3

When Both Conditions Coexist

• The rare combination of hemoptysis followed by rectal bleeding should prompt evaluation for systemic causes including coagulopathy, vasculitis, or vascular malformations 3
• Pulmonary arteriovenous malformations or hereditary hemorrhagic telangiectasia can cause bleeding from multiple sites 3