Green sputum: what it can mean

Sputum is mucus brought up from the lower airways. It may become green as immune cells, debris, and thicker mucus collect during inflammation. A viral chest illness such as Acute Bronchitis can cause this change. Post-nasal drainage from Chronic Sinusitis can also be coughed up and mistaken for lung mucus.

Green sputum may occur with Pneumonia, particularly when paired with fever, chest discomfort, breathlessness, or feeling significantly unwell. Recurrent daily phlegm can occur with Bronchiectasis, and people with COPD may notice a meaningful change from their usual sputum. These conditions need clinical context rather than colour-based diagnosis.

Drink fluids if you can do so safely, rest, and avoid smoking or smoky air. Note how often you cough, the amount and colour of sputum, and whether your breathing or activity tolerance has changed. Follow any existing inhaler or airway-clearance plan exactly as prescribed.

Do not start antibiotics left over from another illness. Antibiotic Treatment is useful only for selected causes and should be chosen after an assessment. A clinician may listen to your chest and decide whether further testing is needed.

Seek urgent care for severe breathlessness, blue or grey lips, new confusion, fainting, severe chest pain, or a rapidly worsening illness. Arrange prompt assessment for fever with breathlessness, pain when breathing, or sputum that is repeatedly changing from your normal pattern.

If you have COPD, bronchiectasis, or another long-term lung condition, contact your usual care team when sputum changes or your rescue treatment is less effective. Persistent or recurrent green sputum also deserves review, even when you otherwise feel fairly well.

Ask: Is the sputum coming from my chest or from nasal drainage? Do my symptoms suggest a chest infection? Should I change any inhaler, airway-clearance, or follow-up plan?