Asthma and coughing up blood

Forceful coughing can sometimes irritate the throat or airway and leave streaks in mucus, but blood can also accompany infection, damaged airways, a clot in the lung or another serious problem. Do not assume asthma explains it.

True coughing up blood, called haemoptysis, comes from the breathing passages or lungs and is often mixed with sputum. Blood from a nosebleed, bleeding gums or vomiting can look similar, so the source is not always obvious. Conditions such as pneumonia, bronchiectasis, tuberculosis, pulmonary embolism and lung cancer can present with haemoptysis. This list does not identify the cause in any individual; an examination and sometimes chest imaging or sputum tests are needed.

Contact a healthcare service promptly for advice and assessment. If possible, note when the bleeding started, whether the blood was streaked through mucus or separate, whether it recurred, and whether you also have fever, chest pain, leg swelling, weight loss or a recent infection. Keep taking prescribed asthma medicines unless a clinician tells you otherwise. Avoid taking extra doses outside your asthma plan in an attempt to treat the bleeding.

Call local emergency services if there is more than a small streak of blood, bleeding continues, or blood appears with severe breathlessness, chest or upper-back pain, a very fast heartbeat, fainting, confusion, blue or grey lips, or signs of shock such as cold clammy skin. These warning signs require urgent assessment because breathing or circulation may be affected. Do not drive yourself if you feel faint or severely short of breath.

Tell the clinician about smoking or vaping, recent travel, contact with tuberculosis, previous clots, lung infections, anticoagulant medicines and any change in your asthma control. Ask what examination or tests can distinguish airway irritation from infection, a clot or structural lung disease, and when you should return if bleeding stops before the appointment.