When to Worry About Coughing Up Blood With Lung Cancer

A tumour or irritated airway can cause blood to mix with mucus. Infection, treatment effects, or another lung condition can also contribute, so the appearance of blood does not by itself show which cause is responsible. Note whether it is streaked, dark, bright red, recurrent, or mixed with clots, and tell the oncology team about any change from your usual symptoms.

Contact your oncology or respiratory team promptly, even if the bleeding has stopped. Keep a record of when it happened and any breathlessness, fever, chest pain, or new cough. Take medicines exactly as prescribed and ask before using products that affect clotting or suppress coughing. If you have an individual emergency plan, follow its instructions and keep the team’s contact details accessible.

Call emergency services for heavy or continuous bleeding, clots that obstruct breathing, severe shortness of breath, chest pain, fainting, confusion, or blue or grey lips. Do not drive yourself if you feel faint or cannot breathe comfortably. A small streak still warrants prompt clinical advice, particularly when it is new, repeated, or accompanied by fever or a sudden decline.

Could my treatment or an infection be contributing? Who should I call outside clinic hours? Which medicines or activities should I avoid? What changes in colour or amount require emergency help?