Diagnosis of pulmonary fibrosis

Nurses play a key role in helping patients and their caregivers navigate the diagnostic process1–6

Diagnosis of pulmonary fibrosis


Early and accurate detection of pulmonary fibrosis is essential in ILDs12 as pulmonary fibrosis takes away lung function and once this is lost, it is lost forever.13,14

Identifying pulmonary fibrosis in patients as early as possible may help to improve their burden of disease, slow decline in daily functioning and quality of life, and reduce the risk of early mortality.12,15,16


Patients should be informed that a diagnosis of ILD requires lung function tests, lung imaging and specialist doctors’ interpretation of their medical history and test results.12,18,19


A multidisciplinary team will determine an ILD diagnosis by considering the patient’s medical history and results from PFTs and HRCTs12,18

Clinical assessment

Clinical assessment
PFTs (FVC and DLco)

PFTs (FVC and DLco)


A multidisciplinary team, including specialist doctors and radiologists, will discuss all available information, which increases the accuracy of ILD diagnosis and prognosis prediction.12,18


Pulmonary function tests (PFTs) Spirometry and diffusing capacity of the lung for carbon monoxide (DLco)

Pulmonary function tests (PFTs)
Spirometry and diffusing capacity of the lung for carbon monoxide (DLco)
What do they assess? The potential relevance of the test results
Spirometry measures a variety of lung function measures, including forced vital capacity (FVC). FVC is a pulmonary function test that calculates the total amount of air that patients can blow out in one breath
DLco measures how efficiently oxygen is transferred from the lungs into the bloodstream20
Low FVC is usually correlated with worsening lung function and may indicate pulmonary problems, even in asymptomatic patients21

DLco is usually lower in patients with pulmonary fibrosis owing to impaired gas exchange22

  • Pulmonary fuction tests (PFTs), including spirometry and lung diffusion test (DLco), are used to examine lung function12,23,24
  • Prior to testing, patients need to tell the doctor about any medications they are taking, as they may need to stop taking certain medications temporarily (i.e. bronchodilators or other inhaled medications)25,26
  • These tests are quick and straightforward to perform25–27
  • These tests are valuable for observing changes in lung functions over time, so they may be performed regularly12,28

Lung diffusion test (DLco)

  • DLco measures how well the lungs allow oxygen and carbon dioxide to enter and leave the blood20


  • Spirometry is a very low-risk test29 and it measures the rate of air flow and lung size27,30
  • Some patients may feel lightheaded or tired from the required breathing effort30

  • They will be asked to take a deep breath in, before blowing as hard as possible into a tube connected to the spirometer30
  • The doctor may administer medicine to help open the airways to investigate if this changes or improves the test results29,30

  • Clips will be placed on their nose to prevent inhalation through the nostrils
  • A mouthpiece will be placed over their mouth
  • They will be asked to take a breath containing a safe amount of carbon monoxide and hold this for a count of ten
  • They will be asked to rapidly exhale the air held in the lungs, which will be collected and analyzed

High-resolution computed tomography (HRCT)

What does it assess? The potential relevance of the test results
Chest HRCT provides detailed images of the lungs and helps to evaluate the extent, distribution and radiological patterns of ILD31–34 

Chest HRCT is the gold standard for early and accurate diagnosis of fibrotic ILDs35
HRCT is used to characterize the type of ILD and in most cases, helps guide the diagnostic approach36

  • A high-resolution computed tomography scan, also known as an HRCT scan, provides doctors with detailed images of their lungs
  • HRCT lung scans may be used to detect tissue damage and fibrosis2,5,12,23
  • HRCT scans use x-rays, so patients will be exposed to radiation.37 The scanners are designed to make sure patients are not exposed to unnecessarily high levels of radiation.38 Patients should speak to their doctor if they have any concerns38

  • They will be placed on a flat table that moves in and out of a round doughnut‑shaped machine
  • Patients will be positioned so that their chest is in the scanner
  • They will be asked to be as still as possible
  • The doctor/technician will monitor the scan from a separate room
  • The scan will last for approximately 15–30 minutes
Laboratory tests

Laboratory tests39

What do they assess? The potential relevance of the test results
  • Full blood cell count
  • Selected serological tests
  • Urine analysis
Laboratory tests may help definitively rule out or confirm specific ILDs, including connective tissue disease-associated ILDs39,40

  • Their doctor may carry out a number of additional tests on their blood and urine to make sure that they are diagnosing the correct disease39

A lung biopsy may be needed in some patients. This is a procedure where the doctor takes a small sample of lung tissue to help diagnose ILD.12,40

You have an important role in coordinating diagnostic tests and helping patients understand the practicalities of them2


Pulmonary fibrosis is unpredictable and regular doctor visits can enable detection of progressive disease; patients should expect further testing including lung imaging, lung function tests, as well as monitoring of their symptoms.11,12,30,35,42,43

Patients should be aware that they may be invited to attend PFTs at regular intervals (e.g. every 3–6 months) as this can help to identify progression of ILD.41,44–50

Patients should understand it is important to assess if their ILD is worsening to ensure they receive appropriate care.12,24,42

Diagnosis and monitoring of ILDs12

Diagnosis and monitoring of ILDs

*Standard of care based on specific ILD. The definition of ILD progession is described in: George PM, et al, Lancet Respir Med. 2020;8:925-934. Adapted from: George PM, et al. Lancet Respir Med. 2020;8:925-954. 
Adapted from: Cottin V, Hirani N, Hotchkin D, et al. Eur Respir Rev. 2018;27(150):180076.


Unclassifiable ILD and idiopathic nonspecific interstitial pneumonia (iNSIP) are not unique diseases, and so when a patient is provisionally diagnosed, further investigation is required to better understand and characterize the type of ILD.52–54

Regular re-evaluation and the search for new information that might increase the confidence in a specific ILD diagnosis is critical,54 as a specific ILD diagnosis may have implications regarding prognosis and treatment.53

HRCT combined with multidisciplinary discussion can enable a confident ILD diagnosis.17,41,55

You have an important role in recognizing any changes in your patients’ wellbeing that may lead to re-evaluation of their ILD diagnosis2

Case study


Case study

Katherine talks about the role of her ILD specialist nurse in her SSc-ILD diagnosis.*

Katherine, age 45, had been experiencing shortness of breath on exertion and a non-productive cough.

Multidisciplinary discussion and review of HRCT scan showed an NSIP pattern and serology was within normal parameters. Failing to identify an underlying cause, the patient was given a diagnosis of iNSIP.

During a routine follow-up appointment with the nurse one year later, Katherine mentioned that she had been recently experiencing pain in the tips of her fingers. The nurse recognized this may be typical of Raynaud’s phenomenon, which is often the earliest clinical manifestation of systemic sclerosis (SSc).56

The nurse reports her findings to the patient’s healthcare team and the rheumatologist requests further serological tests. These results identified serological antibodies that are indicative of SSc-ILD.

This led to a differential diagnosis for Katherine of SSc-ILD.

*Hypothetical patient. Patient case study for illustrative purposes only.

What other resources can help you support your patients in their journey with fibrotic ILD?


  • BAL, bronchoalveolar lavage; DLco, diffusing capacity of the lung for carbon monoxide; FVC, forced vital capacity; HRCT, high-resolution computed tomography; ILD, interstitial lung disease; iNSIP, idiopathic non-specific interstitial pneumonia; MDD, multidisciplinary discussion; NSIP, non-specific interstitial pneumonia; PFT, pulmonary function test; PPF, progressive pulmonary fibrosis; SSc, systemic sclerosis; SSc-ILD, systemic sclerosis-associated interstitial lung disease.

  1. Denton CP, Laird B, Moros L, Flores JLL. Things left unsaid: important topics that are not discussed between patients with systemic sclerosis, their carers and their healthcare professionals–a discourse analysis. Clin Rheumatol. 2021;40:1399–1407.
  2. Grewal JS, Ryerson CJ. A closer look at the multidisciplinary interstitial lung disease clinic: Who, what and how. Respirology. 2021;26:12–13.
  3. McLean AEB, Webster SE, Fry M, et al. Priorities and expectations of patients attending a multidisciplinary interstitial lung disease clinic. Respirology. 2021;26:80–86.
  4. Russell AM, Olive S, Lines S, et al. Contemporary challenges for specialist nursing in interstitial lung disease. Breathe. 2018;14:36–41.
  5. Shaw J, Marshall T, Morris H, et al. Idiopathic pulmonary fibrosis: a holistic approach to disease management in the antifibrotic age. J Thorac Dis. 2017;9:4700–4707.
  6. Vega-Olivo M, Criner GJ. Idiopathic pulmonary fibrosis: A guide for nurse practitioners. Nurse Pract. 2018;43:48–54.
  7. Flaherty KR, Brown KK, Wells AU, et al. Design of the PF-ILD trial: A double-blind, randomised, placebo-controlled phase III trial of nintedanib in patients with progressive fibrosing interstitial lung disease. BMJ Open Respir Res. 2017;4:e000212.
  8. Patterson KC, Strek ME. Pulmonary fibrosis in sarcoidosis. Clinical features and outcomes. Ann Am Thorac Soc. 2013;10(4):362–370.
  9. Caban JJ, Yao J, Bagci U, Mollura DJ. Monitoring pulmonary fibrosis by fusing clinical, physiological, and computed tomography features. Conf Proc IEEE Eng Med Biol Soc. 2011;6216–6219.
  10. Wells AU, Brown KK, Flaherty KR, et al. What’s in a name? That which we call IPF, by any other name would act the same. Eur Respir J. 2018;51(5):1800692.
  11. Cottin V, Wollin L, Fischer A, et al. Fibrosing interstitial lung diseases: knowns and unknowns. Eur Respir Rev. 2019;28:180100.
  12. Cottin V, Hirani NA, Hotchkin DL, et al. Presentation, diagnosis and clinical course of the spectrum of progressive-fibrosing interstitial lung diseases. Eur Respir Rev. 2018;27:180076.
  13. Selman M, King TE, Pardo A; American Thoracic Society; European Respiratory Society; American College of Chest Physicians. Idiopathic pulmonary fibrosis: prevailing and evolving hypotheses about its pathogenesis and implications for therapy. Ann Intern Med. 2001;134(2):136–151.
  14. Molina-Molina M, Aburto M, Acosta O, et al. Importance of early diagnosis and treatment in idiopathic pulmonary fibrosis. Exp Rev Resp Med. 2018;12(7):537–539.
  15. Richeldi L, Collard HR, Jones MG. Idiopathic pulmonary fibrosis. Lancet. 2017;389(10082):1941–1952.
  16. Richeldi L, Varone F, Bergna M, et al. Pharmacological management of progressive-fibrosing interstitial lung diseases: a review of the current evidence. Eur Respir Rev. 2018;27(150):180074.
  17. Walsh SLF. Multidisciplinary evaluation of interstitial lung diseases: current insights. Eur Respir Rev. 2017;26:170002.
  18. De Sadeleer LJ, Meert C, Yserbyt J, et al. Diagnostic ability of a dynamic multidisciplinary discussion in interstitial lung diseases: A retrospective observational study of 938 cases. Chest. 2018;153(6):1416–1423.
  19. Antoniou KM, Margaritopoulos GA, Tomassetti S, Bonella F, Costabel U, Poletti V. Interstitial lung disease. Eur Respir Rev. 2014;23(131):40–54.
  20. Heckman EJ, O’Connor GT. Pulmonary function tests for diagnosing lung disease. JAMA. 2015;313:2278–2279.
  21. Sebastiani M, Vacchi C, Cassone G, et al. Diagnosis, clinical features and management of interstitial lung disease in rheumatic disorders: still a long journey. J Clin Med. 2022;11(2):410.
  22. Wallaert B, Wemeau-Stervinou L, Salleron J, et al. Do we need exercise tests to detect gas exchange impairment in fibrotic idiopathic interstitial pneumonias? Pulm Med. 2012;2012:657180.
  23. Cosgrove GP, Bianchi P, Danese S, Lederer DJ. Barriers to timely diagnosis of interstitial lung disease in the real world: the INTENSITY survey. BMC Pulm Med. 2018;18:9.
  24. Wuyts WA, Wijsenbeek M, Bondue B, et al. Idiopathic pulmonary fibrosis: Best practice in monitoring and managing a relentless fibrotic disease. Respiration. 2020;99:73–82.
  25. O’Connell K. Lung diffusion test. Available at: https://www.healthline.com/health/lung-diffusion-testing. [Accessed January 2023].
  26. NHS. Spirometry. Available at: https://www.nhs.uk/conditions/spirometry/. [Accessed January 2023].
  27. Ranu H, Wilde M, Madden B. Pulmonary function tests. Ulster Med J. 2011;80(2):84–90.
  28. Roofeh D, Jaafar S, Vummidi D, Khanna D. Management of systemic sclerosis-associated interstitial lung disease. Curr Opin Rheumatol. 2019;31:241–249.
  29. Patient. Spirometry. Available at: http://patient.info/health/spirometry-leaflet. [Accessed January 2023].
  30. National Heart, Lung, and Blood Institute. Types of Lung Function Tests. Available at: https://www.nhlbi.nih.gov/health/lung-tests/. [Accessed January 2023].
  31. Mohning MP, Richards JC, Huie TJ. Idiopathic pulmonary fibrosis: the radiologist’s role in making the diagnosis. Br J Radiol. 2019;92(1099):20181003.
  32. Chung J, Goldin J. Interpretation of HRCT scans in the diagnosis of IPF: improving communication between pulmonologists and radiologists. Lung. 2018;196(5):561–567.
  33. Sverzellati N. Highlights of HRCT imaging in IPF. Respir Res. 2013;14 Suppl 1(Suppl 1):S3.
  34. Salaffi F, Carotti M, Di Carlo M, et al. High-resolution computed tomography of the lung in patients with rheumatoid arthritis. Prevalence of interstitial lung disease involvement and determinants of abnormalities. Medicine (Baltimore). 2019; 98(38):e17088.
  35. Chowaniec M, Skoczyńska M, Sokolik R, Wiland P. Interstitial lung disease in systemic sclerosis: challenges in early diagnosis and management. Reumatologia. 2018;56(4):249–254.
  36. Cottin V, Valenzuela C. Diagnostic approach of fibrosing interstitial lung diseases of unknown origin. Presse Med. 2020;49(2):104021.
  37. Pulmonary Fibrosis M. D. HRCT Scans Used to Evaluate IPF. Available at: https://pulmonaryfibrosismd.com/hrct-scans-used-to-evaluate-ipf/. [Accessed January 2023].
  38. NHS. CT scan. Available at: https://www.nhs.uk/conditions/ct-scan/. [Accessed January 2023].
  39. Ryu JH, Daniels CE, Hartman TE, et al. Diagnosis of interstitial lung diseases. Mayo Clin Proc. 2007;82(8):976–986.
  40. Raghu G, Remy-Jardin M, Myers JL, et al; on behalf of the ATS/ERS/JRS/ALAT. Diagnosis of idiopathic pulmonary fibrosis. An Official ATS/ERS/JRS/ALAT clinical practice guideline. Am J Respir Crit Care Med. 2018;198(5):e44–e68.
  41. Geerts S, Wuyts W, De Langhe E, et al. Connective tissue disease associated interstitial pneumonia: a challenge for both rheumatologists and pulmonologists. Sarcoidosis Vasc Diffuse Lung Dis. 2017;34(4):326–335.
  42. Cottin V. Treatment of progressive fibrosing interstitial lung diseases: a milestone in the management of interstitial lung diseases. Eur Respir Rev. 2019;28:190109.
  43. Raghu G, Remy-Jardin M, Richeldi L et al. Idiopathic Pulmonary Fibrosis (an update) and progressive pulmonary fibrosis in adults. An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline. Am J Respir Crit Care Med. 2022;205:e18–e47.
  44. Hoffmann-Vold A, Maher TM, Philpot EE, et al. The identification and management of interstitial lung disease in systemic sclerosis: evidence-based European consensus statements. Lancet Rheumatol. 2020;2(2)E71–E83.
  45. Distler O, Assassi S, Cottin V, et al. Predictors of progression in systemic sclerosis patients with interstitial lung disease. Eur Respir J. 2020;55:1902026.
  46. Iqbal K, Kelly C. Treatment of rheumatoid arthritis-associated interstitial lung disease: a perspective review. Ther Adv Musculoskelet Dis. 2015;7(6):247–267.
  47. Lee AS, Hal Scofield R, Hammitt KM, et al. Consensus guidelines for evaluation and management of pulmonary disease in Sjögren's. Chest. 2021;159(2):683–698.
  48. Mecoli C, Christopher-Stine L. Management of interstitial lung disease in patients with myositis specific autoantibodies. Curr Rheumatol Rep. 2018;20(5):27.
  49. Morisset J, Johnson C, Rich E, et al. Management of myositis-related interstitial lung disease. Chest. 2016;150(5):1118–1128.
  50. Fathi M, Lundberg IE. Interstitial lung disease in polymyositis and dermatomyositis. Curr Opin Rheumatol. 2005;17(6):701–706.
  51. Kinder BW, Collard HR, Koth L, et al. Idiopathic nonspecific interstitial pneumonia lung manifestation of undifferentiated connective tissue disease? Am J Respir Crit Care Med. 2007;176(7):691–697.
  52. Skolnik K, Ryerson CJ. Unclassifiable interstitial lung disease: a review. Respirology. 2016;21(1):51–56.
  53. Brown AW. Unclassifiable interstitial lung disease: time to shrink the black box. Ann Am Thorac Soc. 2018;15(7):806–807.
  54. Guler SA, Ryerson CJ. Unclassifiable interstitial lung disease: from phenotyping to possible treatments. Curr Opin Pulm Med. 2018;24(5):461–468.
  55. Wallace B, Vummidi D, Khanna D. Management of connective tissue diseases associated interstitial lung disease: a review of the published literature. Curr Opin Rheumatol. 2016;28(3):236–245.
  56. Haque A, Hughes M. Raynaud's phenomenon. Clin Med (Lond). 2020;20(6):580–587.
  57. Kolb M, Vašáková M. The natural history of progressive fibrosing interstitial lung diseases. Respir Res. 2019;20:57.
  58. Wijsenbeek M, Cottin V. Spectrum of fibrotic lung diseases. N Engl J Med. 2020;383:958–968.

Resources for patients