Interstitial lung diseases (ILDs) are a group of diffuse parenchymal lung diseases featuring non-infective infiltrations of the lung interstitium and alveoli. Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive form of ILD with characteristic histopathological patterns of usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP) on lung biopsy. Other ILDs include sarcoidosis, hypersensitivity pneumonitis, and ILDs associated with connective tissue diseases. Accurate diagnosis involves correlating clinical, radiological, and histopathological findings.