There are many causes of haemoptysis, including respiratory disease and cardiovascular disease, and lung cancer is one of them.
When lung cancer invades the capillaries of the lungs, patients may experience blood in the sputum or small amounts of haemoptysis. If the tumour invades the large blood vessels in the lungs, it may cause haemoptysis and even suffocation and death. If a patient with haemoptysis is older than 40 years old and has a long history of smoking, they should be on high alert for the possibility of lung cancer and need to be seen promptly for lung cancer screening.