Why does bronchiectasis cause coughing up blood?

Repeated inflammation and infection can damage airway walls. Coughing can then dislodge mucus from an irritated area and bring blood with it. Coughing Up Blood is a common presentation of Bronchiectasis, but blood can also arise from other lung, airway, nose, throat or stomach problems. It can be difficult to tell where blood came from without assessment. Note whether it is streaked through mucus or a larger amount, and whether there is breathlessness, chest pain, fever or dizziness.

Contact a clinician promptly for any new coughing up of blood, even if it is a small streak, particularly if you have known bronchiectasis or a change in mucus. Avoid strenuous exertion until you have advice. If possible, note the colour and amount, take a photo only if this is practical, and tell the clinician about blood-thinning medicines, recent infection symptoms and previous episodes.

Call emergency services if you cough up more than a small streak of blood, bleeding continues, breathing becomes difficult, you have chest pain, fainting, confusion, or feel severely unwell. Sit upright and avoid lying flat while waiting for help. Do not drive yourself if you feel faint or short of breath.

Ask what may be causing the bleeding, whether you need a chest examination, mucus testing or imaging, and when to seek emergency help if it happens again. Ask whether any prescribed medicines should be reviewed, but do not change them without clinical advice.