Causes of coughing up blood

Blood may appear as streaks mixed with mucus after forceful coughing, or as fresh blood. Irritation in the throat or airways can cause small amounts, while pneumonia may bring fever, chest pain, breathlessness, and a productive cough. Bronchiectasis can cause repeated episodes with long-term daily mucus production.

Tuberculosis may be considered when coughing persists with fever, night sweats, weight loss, or relevant exposure. A pulmonary embolism can cause sudden breathlessness, chest pain, a fast heartbeat, or coughing blood. Lung cancer is another possible cause, particularly with a persistent cough, voice change, or unexplained weight loss. Blood from the nose or mouth can sometimes be mistaken for blood from the lungs.

Contact a clinician promptly even if the amount seems small, especially if the symptom is new or recurring. Note the colour, amount, frequency, and whether blood is mixed with mucus. Bring a list of medicines, including blood thinners, and mention smoking, recent travel, infection symptoms, or previous lung disease. Do not drive yourself if you feel faint or breathless.

Call emergency services for more than a trace of blood, ongoing bleeding, severe breathlessness, chest or upper-back pain, blue lips, confusion, fainting, or a very fast heartbeat. Urgent assessment is also needed when coughing blood follows a recent operation, prolonged immobility, or a significant chest injury.

Ask where the blood may be coming from, whether chest imaging or other tests are needed, how your medicines affect bleeding, and what symptoms should send you back to emergency care.