The following differential diagnoses can be considered when small lung volumes are seen:
- pulmonary fibrosis
- prior surgery, e.g. lobectomy, lung volume reduction surgery
- pleural disease, e.g. pleural thickening
- skeletal deformities, e.g. kyphosis, scoliosis
- systemic lupus erythematosus (SLE)
- neuromuscular disorders, e.g. phrenic nerve palsy, poliomyelitis, myasthenia gravis
- pulmonary hypoplasia