Coughing up a blood clot

A clot may form when bleeding in an irritated airway mixes with mucus. Forceful coughing, acute bronchitis, bronchiectasis, and other lung conditions can cause blood-stained sputum. Blood from the nose or throat can also be swallowed and later coughed out. Acid reflux, asthma, allergic rhinitis, and a chronic cough may contribute to irritation but do not explain every clot. The clot's size, recurrence, colour, and accompanying symptoms help a clinician judge the source and urgency.

Sit upright, rest, and avoid strenuous activity or smoking. Note when the clot appeared, whether bleeding continued, and whether you had pain, fever, wheeze, dizziness, or shortness of breath. Bring the clot or a photo only if this can be done without delaying care. Tell the clinician about blood-thinning medicines, recent procedures, injury, infection, and known lung disease. Do not stop prescribed medicines without advice.

Call emergency services if you are breathless, faint, confused, have severe chest pain, blue or grey lips, a rapidly increasing amount of blood, or repeated clots. Seek same-day medical assessment even if you feel well after a single clot, because the source may need examination. Do not drive if dizzy or short of breath.

Ask whether the clot appears to come from the lungs, throat, or nose and whether testing is needed. Describe your cough, smoking or vaping, travel, recent infection, medicines, and any previous episodes. Ask what symptoms should prompt an immediate return.