Accurate and timely diagnosis can help ensure patients have access to appropriate interventions1,2

Recognize signs and symptoms early1

  • Nonproductive (dry) cough3
  • Dyspnea1
  • Dry inspiratory crackles, typically heard at the lung bases1

Other possible signs and symptoms

  • Finger clubbing, fatigue/weakness, unexplained weight loss, loss of appetite1,4

Review tests and scans for additional clues1,5

  • PFTs1,5

─ Reduced FVC, TLC, and DLCO are typical in patients with ILD

─ Spirometry may suggest restriction (low FVC with a normal FEV1/FVC ratio)

─ Normal PFTs do not rule out ILD

  • Walk tests with pulse oximetry can reveal if oxygen levels drop with physical activity5,6
  • Chest x-rays may identify lung abnormalities1
  • An HRCT scan is needed for a more accurate picture of the lungs1

Refer to a lung specialist if ILD is suspected1

  • Once you suspect ILD, refer patients to a lung specialist with expertise to evaluate them further

Not all breathlessness is COPD, asthma, or CHF1,7 Consider ILD in your patients who experience unexplained breathlessness

Listen for the one sound that can help diagnose ILD1

Dry inspiratory crackles at the lung bases can be a key indicator of ILD1

listen for dry inspiratory crackles at the bases of the lungs graphiclisten for dry inspiratory crackles at the bases of the lungs graphic
velcro icon

A particularly distinctive feature of dry inspiratory crackles in ILD is that they sound like *VELCRO® Brand Fastener being peeled apart.1,8

*VELCRO® is a registered trademark. Used with permission.

Features:

  • Typically heard at the lung bases1
  • Inspiratory; can be heard during middle to late inspiration9
  • Does not clear with cough9
  • Short duration9

Listen to the audio clips below and compare dry inspiratory crackles in ILD to other breath sounds.

Dry inspiratory crackles in ILD

Breath sounds of COPD

Normal breath sounds

Note: Recordings were made with a 3MTM Littmann® Electronic Stethoscope 3200 in a clinic setting with patients at rest.†

†3M and Littmann are marks and/or registered marks of 3M.

If you hear dry inspiratory crackles at the lung bases, evaluate further for ILD and consider consulting a lung specialist1

Sounding the ILD alarm: Patients living with ILD share their early symptoms

ILD patient 7

…I had never heard of IPF until I was diagnosed. My symptoms began as what I thought was just a bad cold with fits of dry cough.
-Tom, living with IPF

ILD patient 8

I’d taken an afternoon off work to see my doctor about some pretty mild shortness of breath. […] [My doctor] said that my blood oxygen was so low that I could faint if I went to work. -Vicky, living with MCTD-associated ILD

Pulmonary fibrosis is a common threat across different ILDs graphic Learn about the range of ILDs 
Alert graphic with message to sound the ILD alarm Learn about the role of PCPs 
Document graphic with message about resources for you and your patients View resources 
Magnifying glass graphic with message to discover more about ILD Visit the site 

CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; DLCO, diffusing capacity of the lungs for carbon monoxide; FVC, forced vital capacity; FEV1. forced expiratory volume in 1 second; HRCT, high-resolution computed tomography; IPF, idiopathic pulmonary fibrosis; ILD, interstitial lung disease; MCTD, mixed connective tissue disease; PFT, pulmonary function test; TLC, total lung capacity.

References

  1. Zibrak JD, Price D. NPJ Prim Care Respir Med. 2014;24:14054.
  2. Cottin V et al. Eur Respir Rev. 2018;27(150):18007.
  3. Lederer DJ, Martinez FJ. N Engl J Med. 2018;378(19):1811-1823.
  4. Althobiani M et al. Front Med. 2024;11:1296890.
  5. Ryu JH et al. Mayo Clin Proc. 2007;82(8):976-986.
  6. Raghu Get al. Am J Respir Crit Care Med. 2011;183(6):788-824.
  7. Olson AL et al. Patient Relat Outcome Meas. 2016;7:29-35.
  8. Raghu G et al. Am J Respir Crit Care Med. 2018;198(5):e44-e68.
  9. Moran-Mendoza O et al. BMJ Open Resp Res. 2021;8:1-9.