The natural course of fibrosing lung diseases differs greatly depending on the underlying form. Spontaneous improvements or even complete reversal have been observed in some patients with sarcoidosis. If the disease has been triggered by noxious substances (e.g. cigarette smoking in the cases of respiratory bronchiolitis, RB-ILD) or allergens (e.g. bird feathers in extrinsic allergic alveolitis), the disease undergoes regression in the early stages if the triggering substance is avoided. Other forms respond to treatment with cortisone (if necessary in conjunction with other immunosuppressant substances). Complete regression on treatment is seen, for example, in the case of cryptogenic organising pneumonia (COP).

In the other forms, slow progression of the disease predominates. As a result of the processes causing the changes in the lung, gas exchange is increasingly impaired. Additional administration of oxygen is eventually required. Oxygen therapy is given either only during stress or in the form of long-term oxygen therapy (LOT) including at rest. Depending on the patient’s functional impairment, early retirement is necessary.

Patients with lung fibrosis have increased susceptibility to infections of the airways and lung, which should be treated early and systematically. Hospital admissions are frequently required during such infections.

By considering the prognosis, course to date, age, concomitant diseases and current impairment, lung transplantation is a possibility. This procedure involves not inconsiderable risks and stresses but in many cases can greatly improve the prognosis and quality of life of patients with fibrosing lung diseases.

In view of the relative frequency and aggressive course, so-called idiopathic pulmonary fibrosis (IPF) is of particular importance among the types of fibrosing lung disease. The life expectancy in this form of lung fibrosis is greatly reduced.