What is smoking-associated interstitial lung disease? Interstitial lung disease is a general term for a group of diffuse lung diseases with progressive dyspnea as the main clinical manifestation, including more than 200 diseases with different etiologies. Among them, fibrotic lung disease, which is closely related to smoking, is called smoking-associated interstitial lung disease. It is well known that smoking is an “invisible killer” that threatens human health. According to data published by the World Health Organization, cigarette smoke contains more than 5,000 compounds that are harmful to the human body in many ways, most closely related to the respiratory system. Smoking can not only cause lung cancer and chronic obstructive pulmonary disease, but can also lead to pulmonary fibrosis. Smoking-associated interstitial lung disease is a general term for a group of diseases, including respiratory bronchitis with interstitial lung disease, desquamative interstitial pneumonia, pulmonary Langerhans cell histiocytosis, and pulmonary fibrosis combined with emphysema. Do I have to quit smoking in smoking-associated interstitial lung disease? Smoking cessation is the primary treatment for smoking-associated interstitial lung disease, and a proportion of patients with smoking cessation have remission or remain stable, with improvement in chest imaging and lung function, especially in patients with respiratory bronchiectasis with interstitial lung disease, desquamative interstitial pneumonia, and pulmonary Langerhans cell histiocytosis. What is the prognosis for smoking-associated interstitial lung disease? Most patients with respiratory fine bronchitis with interstitial lung disease have a good prognosis. In a few patients, symptoms and lung function may worsen even after smoking cessation and glucocorticoid administration. The prognosis for desquamative interstitial pneumonia is good, with 5- and 10-year survival rates of 95% and 70%, respectively. The disease usually progresses slowly and acute exacerbations are rare, with only a few patients progressing to respiratory failure and even death. Pulmonary Langerhans cell histiocytosis has a tendency to remit spontaneously, with 75% of patients having stable or improving disease 6-24 months after quitting smoking, and a minority of patients having progressive disease. Patients with pulmonary fibrosis combined with emphysema usually have irreversible lung lesions that gradually deteriorate and are prone to combined pulmonary hypertension and respiratory failure.