Idiopathic lung fibrosis, or idiopathic pulmonary fibrosis, is a disorder in which the lungs are damaged and thickened, scarred tissue develops and reduces lung function. The term idiopathic means that the cause of the disease is not known. Symptoms of idiopathic lung fibrosis include worsening breathlessness, which may be associated with coughing. Lung fibrosis typically progresses over time, but the rate of progression is difficult to predict. Although idiopathic lung fibrosis has no cure, drugs and other treatments are available which can relieve symptoms; in some cases, a lung transplant may be carried out.
While some types of fibrosis affecting the lungs are known to be caused by factors such as drugs, radiotherapy and asbestos, in most cases, no cause can be identified and idiopathic fibrosis is the diagnosis. In idiopathic lung fibrosis, it is thought that the tiny air sacs in the lungs may be damaged by an unknown process and that the healing response that follows is too strong. As a result, excessive amounts of fibrous tissue form in the walls of the air sacs, creating a thick barrier, which prevents oxygen from passing though and into the blood. Reduced oxygen in the blood leads to shortness of breath, which increases as the fibrosis progresses. Tiredness, coughing and swelling of the ends of the fingers may also occur.
Middle-aged people are most likely to be diagnosed with the disease, as are smokers, and the condition occasionally runs in families. The diagnosis of idiopathic lung fibrosis may be partly confirmed by listening to chest sounds through a stethoscope, in which case characteristic crackles will be heard. Lung scarring may be seen on a chest X-ray but a computerized tomography (CT) scan may be required to show more detail. Procedures that test the function of the lungs typically show a decrease in performance. Sometimes it may be necessary to take a sample of lung tissue and analyze it microscopically in order to make a definite diagnosis.
As many medications have side effects, treating idiopathic lung fibrosis may involve doing nothing, especially in the case of elderly people whose symptoms are not troublesome, and in whom the disease is not progressing quickly. Drugs sometimes given include steroids and medication which suppresses the immune system. It is important to give up smoking; the use of exercises and breathing techniques may also be beneficial. In more severe cases, oxygen may be required and, where other treatments have failed to work, a lung transplant may be considered.