Foamy Sputum: Causes Ranging from Pulmonary Edema to Benign Factors

Differential Diagnosis of Frothy Oral Discharge

Serious Cardiopulmonary Causes

• Pulmonary Edema (Cardiogenic): Pink, frothy sputum; orthopnea, crackles, cardiomegaly—medical emergency.
• Noncardiogenic Pulmonary Edema (ARDS): Similar appearance; due to sepsis, trauma, aspiration.
• Severe Asthma/COPD Exacerbation: Thick, mucoid, sometimes frothy.
• Pneumonia: Purulent, may be frothy if alveolar flooding.
• Tuberculosis: Blood-tinged, frothy; chronic cough, weight loss, night sweats.

Benign/Transient Causes

• Carbonated beverages, beer, toothpaste foam
• Smoking (chronic bronchitis)
• Stimulant use (cocaine, methamphetamine)
• GERD/LPR: acid foam reflux
• Hiatal hernia exacerbating reflux

Action

Pink frothy sputum + dyspnea = call 911. Otherwise, see a clinician for evaluation if persistent or accompanied by fever, weight loss, hemoptysis, or respiratory distress.