What should you know about a green cough with a little blood?

Green sputum reflects immune cells and mucus in the airways; its colour alone cannot show whether an infection is bacterial or whether antibiotics are needed. A forceful or frequent cough can irritate the throat or airway lining and leave a small red streak. Acute Bronchitis and Common Cold can cause cough and mucus, while asthma, allergic rhinitis, acid reflux or bronchiectasis may contribute to persistent cough in different ways. Bronchiolitis is more relevant in young children.

Blood may also come from the nose or gums and mix with mucus. The amount, recurrence, duration and accompanying symptoms matter more than colour alone.

Contact a clinician promptly to describe the blood, sputum colour, cough duration and any fever, breathlessness or chest discomfort. Rest, drink fluids and avoid smoking or second-hand smoke. Do not start leftover antibiotics. If the cough continues or returns, assessment may look for asthma, bronchiectasis, chronic cough or another airway cause.

Seek emergency care for more than a small streak, repeated or increasing blood, trouble breathing, blue lips, chest pain, fainting, severe weakness or confusion. Urgent assessment is also needed if coughing blood follows a chest injury or occurs with a severe sudden illness. Children with breathing difficulty, poor feeding or unusual sleepiness need immediate help.

Record when the blood appeared, how it looked, how often it happened, and whether it came with fever, wheeze, chest pain, weight change or night sweats; share this with the clinician.