Pulmonary fibrosis, short for “interstitial lung disease,” is commonly understood as the result of the body’s own repair of damage to the lungs and is characterized by diffuse chronic inflammation of the alveolar wall and interstitial fibrosis. The interstitial tissue of the lung is composed of collagen, elastin and proteoglycans. When fibroblasts are chemically or physically injured, they secrete collagen to repair the interstitial tissue of the lung, resulting in pulmonary fibrosis. Pulmonary fibrosis is a diffuse group of parenchymal lung diseases with insidious onset and progressive exacerbation. The main symptom of pulmonary fibrosis is dyspnea, with no cough in the early stages. As the disease progresses, there is generalized weakness, loss of weight, loss of appetite, and joint pain. The acute form may have fever. In the late stage, respiratory failure, mainly hypoxemia, may occur. The treatment of pulmonary fibrosis is based on the principles of infection control and delaying the development of pulmonary fibrosis, and symptomatic management. The drug of choice for idiopathic pulmonary fibrosis is pirfenidone, but it must be prescribed by a physician in a respiratory specialist clinic after the pathological type of interstitial lung disease has been defined. Home oxygen therapy is available for advanced pulmonary fibrosis, and nebulized oxygen administration is commonly used in the acute phase.