What should you know about coughing up pure blood?

Blood coughed from the lower airways is called haemoptysis. It can follow airway irritation or an infection such as pneumonia. Bronchiectasis can cause bleeding from widened, inflamed airways. Less common but serious causes include a pulmonary embolism, tuberculosis or lung cancer. The appearance does not show which cause is present, and blood from the nose or mouth can sometimes be mistaken for blood from the chest.

Describe whether the blood was bright red, clotted, frothy or mixed with mucus. Note chest pain, fever, breathlessness, dizziness, night sweats and weight change, then share these details with a clinician.

Arrange urgent medical advice even if the bleeding has stopped, particularly when the source is unclear or the symptom is new. Sit upright, rest and avoid smoking or strenuous activity while arranging care. Do not take cough remedies or blood-thinning medicines for this symptom without checking with a clinician. Assessment may include a chest examination, blood tests or imaging, depending on your symptoms and history.

Call emergency services immediately if blood is coming out repeatedly or heavily, you cannot catch your breath, you have sudden chest or upper-back pain, faintness, blue lips or confusion. Do not drive yourself if you feel weak or breathless. Even a small amount needs prompt review when accompanied by fever, a rapid heartbeat or a history of lung disease.

Ask where the blood may be coming from, which tests are appropriate, whether your medicines affect bleeding, and what exact change in amount or symptoms should send you to emergency care.