Coughing up dark green mucus with blood

Dark green mucus often reflects thick airway secretions containing inflammatory cells; it does not by itself prove that bacteria are the cause. Blood can appear when coughing irritates inflamed airway surfaces. Pneumonia may present with fever, chest pain, breathlessness, and discoloured phlegm. Bronchiectasis can cause recurring large amounts of mucus and occasional bleeding. A pulmonary embolism, tuberculosis, or lung cancer can also cause coughing blood, although the mucus colour cannot distinguish these conditions. The full pattern and examination guide the next step.

Arrange prompt clinical advice, particularly if the cough is worsening or the blood returns. Record how long the mucus has been green, whether it smells unusual, the amount of blood, and any fever, wheeze, chest pain, or reduced exercise tolerance. Rest, avoid smoking and vaping, and drink fluids if medically suitable. Do not use leftover antibiotics or assume green mucus alone means you need them.

Call emergency services for heavy or continuing bleeding, severe breathlessness, chest pain, fainting, confusion, or blue lips. Seek same-day assessment for a high fever with marked weakness, rapidly worsening breathing, or a sudden change in the amount of blood. Sit upright while waiting for help and avoid driving if breathless or dizzy.

Ask whether your symptoms fit an airway infection or another lung problem, whether you need a chest examination, imaging, or a sputum sample, and whether treatment is indicated. Ask what signs mean you should return urgently.