Bad cough and coughing up blood: what to know

Blood may come from irritated airways after forceful coughing, but it can also occur with pneumonia or bronchiectasis, where damaged airways produce repeated phlegm and infections. Tuberculosis is another possible cause, especially with a prolonged cough, fever, night sweating or weight loss.

A pulmonary embolism can cause sudden breathlessness and chest pain with coughing up blood. Lung cancer may present with coughing up blood, particularly when a cough is new or changing, although other explanations are possible. Blood from the nose, mouth or stomach can sometimes be mistaken for blood from the lungs, so describe its appearance and how it appeared.

Stop strenuous activity, sit upright and arrange medical advice promptly, even if the amount seems small or the symptom stops. Note the colour, approximate amount, whether it was mixed with mucus, and whether it followed a severe bout of coughing.

Take a photo if safe and useful for showing a clinician, and bring a list of medicines, especially blood thinners. Do not take leftover antibiotics or stop prescribed medicine without advice. Avoid smoking and vaping while waiting for assessment.

Call emergency services immediately if bleeding is more than streaks, continues, or comes with severe breathlessness, chest pain, fainting, confusion, a very fast heartbeat or blue lips. Sudden symptoms after surgery, prolonged immobility or a long journey also need emergency attention.

Seek same-day care for any unexplained episode, fever, worsening cough, significant weakness, or repeated blood-stained mucus. Do not drive yourself if you feel faint or short of breath. A clinician may need to examine your chest and decide whether tests are needed.

Ask where the blood may be coming from, what warning signs to monitor, and whether you need chest imaging or other tests. Tell the clinician about infection symptoms, smoking history, travel or exposure risks, previous lung problems, recent procedures and every medicine you take.