Which term describes thick mucus from the lungs expelled through the mouth?

• A. Sputum
• B. Phlegm
• C. Mucus
• D. Expectorate

Answer: (A)

Sputum is the term used for material coughed up from the lower airways. When thick mucus is expelled from the lungs through the mouth, clinicians call it sputum. This word specifically identifies the substance that comes from the respiratory tract and can be analyzed in the lab for infection or inflammation.

Phlegm is a term you’ll hear in everyday language, but in medical context sputum is the more precise label for the actual expelled material from the lungs. Mucus is the broader secretion produced by mucous membranes, not limited to the lungs or the act of coughing it up. Expectorate describes the act of coughing up and spitting out mucus, not the substance itself.