Coughing up phlegm

Coughing up phlegm can reflect mucus being cleared from irritated airways, but its pattern and accompanying symptoms matter. Phlegm may occur with a common cold, acute bronchitis, asthma, bronchiectasis or bronchiolitis. Acid reflux and allergic rhinitis can also contribute to throat clearing or cough. Colour alone cannot identify the cause or decide whether antibiotics are needed.

Record how long the mucus has been present, whether it is thick or difficult to clear, and whether there is fever, wheeze, chest pain or breathlessness. Bronchiectasis may cause a recurring productive cough and needs a clinician-led plan. Asthma can produce mucus alongside wheeze or chest tightness. A young child with bronchiolitis may cough while breathing faster or feeding less. Reflux can cause a cough without mucus from the lungs, particularly after meals or when lying down.

Drink fluids regularly, rest, and avoid smoke and other airway irritants. Gentle movement may help some people clear mucus, but stop if breathing becomes difficult. Do not suppress a productive cough with someone else’s medicine, and do not start leftover antibiotics. Note the mucus colour, amount and any blood, while remembering that these observations are clues rather than a diagnosis. A clinician can decide whether examination, inhaled treatment or further tests are needed.

Seek emergency help for significant breathing difficulty, blue lips, confusion, fainting, severe chest pressure or more than a small streak of blood in phlegm. Arrange prompt medical review for repeated blood-streaked mucus, worsening breathlessness, persistent fever, chest pain, dehydration or a cough that is not settling. People with chronic lung disease should follow their personalised action plan and seek advice when their usual mucus or breathing pattern changes.

What might be causing my productive cough? Does the mucus pattern suggest an airway condition or infection? Do I need a chest examination, sputum sample or breathing test? What should I do if the amount or colour changes?