It's Not JUST Idiopathic Pulmonary Fibrosis Study

Inclusion Criteria * Male or female aged ≥ 18 years old * Able and willing to give written informed consent * Recently diagnosed \[defined as diagnostic CT scan or surgical lung biopsy (if applicable) \>1st May 2017\] * An MDT diagnosis of fibrotic interstitial lung disease (reticulation, traction +/- honeycombing) Sub Groups * Rheumatoid arthritis (rheumatologist diagnosed with anti-CCP antibodies and/or Rheumatoid Factor positive) * Asbestosis (appropriate occupational history and radiological evidence of asbestos exposure) * Chronic HP in accordance with consensus criteria (appropriate exposure history, radiological features +/- avian and fungal precipitins) * Unclassifiable fibrotic lung disease (fibrotic lung disease otherwise unclassifiable despite extensive clinical and radiological examination) * IPF in accordance with consensus criteria (ATS/ERS/JRS/ALAT guidelines) as controls Exclusion Criteria: * Participating in an interventional clinic trial * Asymptomatic Interstitial Lung Abnormalities (ILA) and normal lung function. * Change in clinical phenotype from initial radiological diagnosis to screening * Acute Hypersensitivity Pneumonitis. * Participants who do not possess a smartphone or have a valid email address (necessary for the home FVC readings)