How is coughing up phlegm treated?

Phlegm is mucus from the airways. It can increase during acute bronchitis or pneumonia, and may persist with COPD or bronchiectasis. Mucus draining from chronic sinusitis can also trigger throat clearing and coughing. Colour alone cannot identify the cause, so a clinician may ask about duration, fever, breathlessness, chest pain, smoking, wheeze, and changes in the usual amount or thickness.

Drink regularly unless you have been advised to restrict fluids, avoid smoke and dusty air, and keep gently active if you feel well enough. Ask a clinician or respiratory therapist to show you airway-clearance techniques when mucus is difficult to shift. Use prescribed inhalers with the correct technique. Antibiotic treatment is appropriate only when a clinician identifies a bacterial infection or another clear indication; do not use leftover tablets. A sample of sputum may sometimes help guide care.

Arrange an assessment for phlegm that persists, increases, smells unusual, or changes alongside fever or worsening breathlessness. Seek urgent help for severe breathing difficulty, chest pain, confusion, blue lips, dehydration, or blood in the mucus. People with COPD or bronchiectasis should follow their personalised flare-up plan and contact their care team when usual symptoms change.

Could this be an infection or a change in an existing lung condition? Do I need a sputum test? Which airway-clearance method or inhaler is suitable, and when would antibiotics help?