This may be either slow, long-term bleeding or it may be sudden and very serious. It may also be localised to one part of the bronchial tubes (Focal pulmonary haemorrhage) or generalised throughout the lungs (diffuse pulmonary haemorrhage).
Focal pulmonary haemorrhage
When localised, the bleeding may complicate a severe chest infection or pneumonia, bronchiectasis (especially in cystic fibrosis), TB, lung abscess, fungal infection, trauma (including aspiration of foreign body), lung cyst, aspergilloma (a fungus ball which may grow in lung cysts), lung tumours or a congenital abnormality of the blood vessels (pulmonary artero-venous malformation).
Diffuse pulmonary haemorrhage
This usually involves bleeding into the lung from small blood vessels. Some diseases are associated with inflammation of the lung capillaries. These conditions include Wegener’s granulomatosis, Goodpasture’s syndrome, systemic lupus erythematosis, Henoch-Schonlein purpura), pulmonary hypertension, heart diseases with lung congestion, problems with blood clotting and pulmonary haemosiderosis. This is a rare, but serious condition occurring in infants and young children in which there is recurrent bleeding into the alveoli and the tissue around the lung. It presents with vomiting of blood, anaemia and shadows seen on chest X-ray. It may occur on its own (idiopathic) or be associated with Good-pastures syndrome, allergy to cows’ milk (Heiner’s syndrome), rheumatoid autoimmune diseases or heart diseases.
Goodpasture’s syndrome, Henoch-Schonlein purpura and blood clotting abnormalities will be associated with blood loss elsewhere, especially in the urine.
