Interstitial lung diseases (ILDs) lead to activity limitations and participation restrictions, often resulting in disability. Disability should be assessed using the biopsychosocial model of the International Classification of Functioning, Disability, and Health (ICF), as recommended by the WHO.

To correlate the ICF domains to explore how bodily functions are associated with activity limitations and participation restrictions in patients with ILD.

A cross-sectional observational study involving patients with ILD, diagnosed according to the guidelines of the American Thoracic Society (ATS) and the European Respiratory Society (ERS), who had a stable clinical condition for at least three months. Pulmonary function was assessed using spirometry and respiratory muscle strength; activity was measured through the Incremental Shuttle Walk Test (ISWT) and the Six-Minute Walk Test (6MWT); and participation was evaluated using the Saint George's Respiratory Questionnaire (SGRQ).

Of the 25 patients, the majority were men aged over 60 years, and it was observed a positive and moderate correlation (r = 0.45; p < 0.05) was found between activity and pulmonary function. However, the 6MWT showed a negative and moderate correlation with dyspnea (r = -0.52; p = 0.007). The participation component (SGRQ) did not show a significant association with the other components.

A significant relationship was found between the activity component and body functions, whereas participation was not linked to these components. This suggests that restrictions in participation are multifactorial, necessitating a comprehensive approach that goes beyond the traditional biomedical model and includes contextual factors.

These findings emphasize the need for a biopsychosocial approach in rehabilitation, addressing not only physical function but also social and environmental barriers. Personalized interventions incorporating psychological and social support are essential to effectively enhance participation and patient outcomes.