Double lung fibrotic foci have symptoms such as cough, chest tightness after activity, wheezing, dyspnea, generalized weakness, and long onset of disease. 1. Dyspnea: chest tightness after activity, gradually aggravated, may be accompanied by wheezing, late stage may be complicated by pulmonary heart disease, pulmonary hypertension. 2. Systemic symptoms: systemic manifestations of emaciation, fatigue, loss of appetite, joint pain, anemia, malnutrition. 3. Cough: cough mostly irritating dry cough, cough a small amount of mucous sputum, secondary infection appears mucopurulent sputum, occasionally see blood sputum, can be accompanied by fever. 4. Long duration of disease onset: the onset of the disease is insidious, and there are obvious individual differences in the speed of progression of the disease, which develops into respiratory failure and cor pulmonale after a few months to a few years. The average survival time after disease onset is 3 to 5 years.