Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: September 20, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Differential Diagnosis for Greenish Sputum

Single Most Likely Diagnosis

  • Chronic Bronchitis: This condition is characterized by the production of excess mucus, which can appear greenish due to the presence of pus. Chronic bronchitis is a common cause of greenish sputum, especially in smokers or those with a history of respiratory infections.

Other Likely Diagnoses

  • Pneumonia: Bacterial pneumonia can cause the production of greenish or yellowish sputum due to the presence of pus. This diagnosis is likely in patients with symptoms such as fever, cough, and shortness of breath.
  • Bronchiectasis: This condition involves the permanent enlargement of parts of the airways and can lead to the production of large amounts of greenish sputum. Patients with bronchiectasis often have a history of recurrent respiratory infections.
  • Cystic Fibrosis: Although more common in children, cystic fibrosis can also present in adults with symptoms such as greenish sputum production, recurrent respiratory infections, and malabsorption.

Do Not Miss Diagnoses

  • Lung Abscess: A lung abscess can cause the production of foul-smelling, greenish sputum. This condition requires prompt diagnosis and treatment to prevent serious complications, including sepsis and respiratory failure.
  • Tuberculosis: Although less common in some regions, tuberculosis (TB) can cause greenish sputum, especially in patients with advanced disease. TB is a critical diagnosis not to miss due to its public health implications and the need for specific treatment.
  • Aspiration Pneumonia: Aspiration of food, liquids, or other materials into the lungs can lead to pneumonia, which may present with greenish sputum. This condition is particularly dangerous and requires immediate medical attention.

Rare Diagnoses

  • Allergic Bronchopulmonary Aspergillosis (ABPA): This condition occurs in people with asthma or cystic fibrosis and involves an allergic reaction to Aspergillus fungi. It can cause the production of greenish sputum plugs.
  • Bronchial Adenoma: A rare tumor of the airways, which can cause obstructive symptoms and the production of greenish sputum due to secondary infection.
  • Parasitic Infections: Certain parasitic infections, such as paragonimiasis (lung fluke infection), can cause greenish sputum, although these are rare in most parts of the world and typically associated with specific travel or exposure histories.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.