Jin-shui Huan-xian Formula for Retarding the Decline of Pulmonary Function in IPF

Inclusion Criteria: 1. Patients who meet the diagnostic criteria for IPF. 2. Pulmonary function: The percentage of forced vital capacity (FVC) to the predicted value is ≥ 50%; and the percentage of the diffusing capacity of the lung for carbon monoxide (DLCO) to the predicted value is ≥ 30%. 3. Patients who meet the syndrome - differentiation criteria for lung - qi deficiency syndrome, lung - and - kidney qi deficiency syndrome, etc. 4. Aged between 40 and 85 years old. 5. Patients who voluntarily accept the treatment and sign the informed consent Exclusion Criteria: 1. Patients in the acute exacerbation phase of IPF. 2. Patients complicated with other pulmonary diseases such as chronic obstructive pulmonary disease (COPD), lung cancer, active pulmonary tuberculosis, bronchiectasis, and pulmonary embolism. 3. Patients with severe joint, peripheral nerve, and peripheral vascular diseases that affect limb movement and who are bed - ridden for a long time and cannot complete the six - minute walk test. 4. Patients complicated with severe cardiovascular and cerebrovascular diseases (malignant arrhythmia, unstable angina pectoris, acute myocardial infarction, heart function grade 3 or above, stroke, cerebral hemorrhage, etc.). 5. Patients complicated with liver diseases such as cirrhosis or secondary portal hypertension, bleeding caused by esophageal and gastric varices, patients with kidney diseases requiring dialysis or kidney transplantation, or patients with abnormal liver and kidney functions (ALT, AST, and BUN are 1.5 times higher than the upper limit of the normal range, and blood Cr is higher than the upper limit of the normal range). 6. Patients with unclear consciousness, various mental illnesses, etc., who cannot communicate normally. 7. Pregnant or lactating women and patients with a recent plan for pregnancy. 8. Patients who have participated in other clinical trials within 1 month before enrollment. 9. Patients known to be allergic to any of the test medications and their components.