Coughing up a little blood

Blood may come from irritated airways after a hard cough or infection. Pneumonia can cause blood-streaked mucus alongside fever, chills, chest pain, or breathlessness. Bronchiectasis may produce repeated episodes with large amounts of mucus. Tuberculosis and lung cancer are less common possibilities that a clinician considers alongside symptoms, examination findings, smoking history, and risk factors. A clot in the lung, called pulmonary embolism, can cause sudden breathlessness or chest pain with coughing up blood.

Stop and record the episode: note the colour, approximate amount, whether it was mixed with mucus, and whether it followed forceful coughing. Contact a clinician promptly if it recurs or you have a persistent cough. Do not smoke or vape, and take your medicine list with you. If you use an anticoagulant, tell the clinician rather than changing the dose yourself.

Call emergency services for heavy or ongoing bleeding, severe breathing difficulty, sudden chest pain, fainting, confusion, blue lips, or a very fast heartbeat. Sudden symptoms after prolonged immobility, surgery, or a long journey also need urgent evaluation. Do not drive yourself if you feel faint or breathless.

Ask whether the blood appears to come from the lungs, nose, or digestive tract; what tests may be appropriate; and how to respond if it happens again. Mention fever, weight change, night sweats, travel, smoking, and all medicines.