Sputum volume

Normal people have no sputum or only a small amount of foamy or mucus. In respiratory diseases, the amount of sputum can increase, exceeding 50-100ml. Those with the highest sputum volume are seen in bronchiectasis, pulmonary abscess, pulmonary edema, or cavitary lesions of the lung; when a lung abscess or empyema ruptures into the bronchi, the sputum may be purulent. During the treatment of the disease, if the amount of sputum is reduced, it generally indicates that the condition is improving; if the bronchial obstruction prevents the sputum from being discharged, the decrease in sputum volume indicates that the condition is developing.