Coughing up blood once

A hard cough can irritate the lining of the airways and leave a small red streak in mucus. Blood can also come from the nose, gums, or throat. A single episode can occur with pneumonia or another chest infection, bronchiectasis, pulmonary embolism, tuberculosis, or lung cancer, so stopping does not reveal the cause. Colour, amount, recurrence, fever, breathing difficulty, chest pain, and medication history help a clinician decide what assessment is needed.

Record the time, amount, colour, and whether the blood followed coughing, throat clearing, or vomiting. Arrange prompt medical advice even if it has stopped, particularly if you smoke, take anticoagulants, or have lung disease. Rest upright, avoid smoking and strenuous exercise, and do not start aspirin or anti-inflammatory medicines for this symptom without advice. If it happens again, note whether the amount is increasing.

Go to emergency care for more than a small streak, renewed or ongoing bleeding, breathlessness, chest pain, faintness, confusion, a racing heartbeat, or severe weakness. Seek same-day care for fever, worsening cough, or a general deterioration. Ask another person to accompany you if you feel dizzy.

Ask what source is most likely after examining you, whether you need chest tests, and what changes should trigger emergency care if the symptom returns.