Blood in cough: what should you know?

A small streak may follow forceful coughing, a throat irritation, or inflammation in the breathing tubes. Blood can be mixed with mucus, pink, red, or rust-coloured. A cold or acute bronchitis can irritate airway surfaces; asthma, bronchiectasis, and a persistent cough can also need evaluation. Nasal bleeding or gum bleeding may drain backward and be mistaken for blood from the chest. The appearance alone cannot identify the source.

Arrange prompt medical advice for any unexplained blood, even if the amount seems small. Note whether it came with phlegm, how often it happened, its colour, and whether coughing, fever, chest discomfort, wheezing, or breathlessness accompanied it. Avoid smoking and strenuous activity until you have advice. Do not start or stop prescribed medicines, including blood thinners, without speaking with a clinician.

Seek emergency help if bleeding is more than a few streaks, continues, or makes breathing difficult. Urgent assessment is also needed for chest pain, faintness, confusion, blue lips, a fast worsening illness, or blood after a chest injury. If you feel stable but the symptom returns, contact a doctor promptly rather than waiting for it to settle.

Ask whether the blood seems to come from the nose, throat, or lower airways; which examination or tests may clarify the source; and whether your medicines, smoking history, or a long-standing cough affect the assessment.