Idiopathic pulmonary fibrosis (IPF) is a common disease of the pulmonary insterstitium, some studies cite it as the most common form of interstitial pneumonia, and is in general considered a more common disease of the pulmonary interstitium. As the name implies, the exact etiology of the disease is unknown. Thanks to numerous studies in recent decades, the number of which has grown rapidly since the introduction of the first effective therapy, significant progress has been made in understanding the course of the disease and its mechanisms. Despite the progress in understanding the disease, its exact cause is still a mystery. Risk factors are known, there is a much higher chance of developing IPF in patients who are long-term smokers, also it's more common in men and women who have worked or still work in the wood od metal industry. Originally though to be a type of chronic inflammation limited to the lungs, the most recent theory is that IPF is caused by epithelial cells of alveoli that can be abnormally activated due to microscopic damages of the lung parenchyma. Because of that abnormal activation cells begin to create mediators that stimulate the creation of fibroblasts and myofibroblasts, the formation on fibroblastic focci (which are used as a diagnostic criterion) and cause attraction of local fibrocytes. The result of these changes and activations is irreversible destruction of the pulmonary parenchyma which in turn leads to a decrease of overall pulmonary capacity. Characteristic to IPF is a long and complicated diagnosis and poor prognosis. Average survival after a successful diagnosis is about 3 years. The clinical course has proven to be heterogenous, different from patient to patient, some may have a slow others a rapid progression, even stages of rest i which there are no changes to the parenchyma. All of the different disease progressions have in common that at any time they can be interrupted by acute exacerbations, a sudden deterioration in lung function and worsening dyspnea. Diagnosis of the disease is performed by radiological and pathohistological confirmation of the usual interstitial pneumonia (UIP) pattern and by eliminating all other possible diseases that manifest with said pattern.