The prevalence of ILD varies globally due to differences in diagnostic criteria and reporting. It is estimated that the prevalence in the United States is around 50-100 cases per 100,000 people. Specific types of ILD, such as idiopathic pulmonary fibrosis (IPF), have a lower prevalence, affecting about 13-20 per 100,000 individuals. The numbers are thought to be underreported due to the challenges in diagnosis.
