Looking Closer at Chronic Cough

What Causes Chronic Cough?

Chronic cough is a complicated condition that researchers are still working to fully understand. It has been proposed that chronic cough in IPF and non-IPF ILD is likely the result of multiple factors, including changes in the lungs and how the brain processes cough signals. Coughing is controlled by a “communication system” between the lungs, the nerves, and the brain. In patients with IPF and non-IPF ILD, this communication system can become out of balance, contributing to chronic cough.1

Factors Driving Chronic Cough

Sensitive Nerves in the Airways

In IPF and non-IPF ILD, the lungs become scarred and inflamed over time.1 This scarring can irritate the small nerves in your lungs that help control your cough reflex.2 When these nerves become overly sensitive, they can overreact and send signals to the brain to cough when they don’t need to.3 Even small things, like talking, laughing, or breathing in cold air, can generate a dramatic cough response.4

Changes in Lung Structure

As IPF and non-IPF ILD progress, the lungs can become stiff from scar tissue. This can put pressure on the nerves that trigger coughing and make your body more likely to cough, even when it doesn’t need to.5 Over time, these nerves and the brain can become extra sensitive, meaning the cough may continue even if the scarring doesn’t get worse. This can create a cycle where coughing persists on its own, creating a cycle that’s hard to break.6

Misinterpreted Signals in the Brain

Research shows that over time, the brain can become more sensitive to signals coming from the lungs.7 When the cough reflex is triggered repeatedly, the brain starts to “learn” this response and may begin to activate it even when it’s not truly needed.8

Chronic Cough in Their Own Words

“My cough has been debilitating. It often very quickly will escalate from a few coughs to very harsh coughs, to vomiting to lack of ability to you know suck air in.“

— Cheri, US Patient with Idiopathic Pulmonary Fibrosis

*This quote is from a patient who was compensated for their participation in a patient advisory board.

The Cough Reflex

Your body has special sensors, called cough receptors, in places like your lungs, throat, and nose. These receptors are designed to protect you by triggering a cough when something irritates your airways.9

When the airways are irritated, specialized sensory receptors in the lungs become activated.9

These receptors send a nerve signal to an area of the brainstem, which acts as the body’s “cough center.”10

Your body’s cough center processes this input, and if the signal is strong enough, then it outputs a nerve signal to your chest, diaphragm, and abdominal muscles.

These muscles contract, and your body produces a forceful cough intended to clear the airways.9

In IPF & non-IPF ILD Patients with chronic cough,

the cough reflex can become overactive, leading to frequent coughing and severe fits. Identifying specific triggers can be especially difficult due to the combination of factors that likely contribute to the cough. When this cough lasts longer than 8 weeks, it is defined as chronic cough.11

Common Triggers of Cough12

Talking

Aerosols & Perfume

Stress

Talking

Laughing

Change in Temperature

Physical Activity

Poor Air Quality

Crying

Humidity

Change in Position

Singing

References

  1. Lim, C. Y., Khan, S. W., Alsibai, T., & Sathiyamoorthy, G. (2025). Examining Cough’s Role and Relief Strategies in Interstitial Lung Disease. Journal of Clinical Medicine, 14(1), 291. https://doi.org/10.3390/jcm14010291
  2. Chung, K.F., Birring, S.S., Morice, A.H. et al. Tackling the Neuropathic Cough of Idiopathic Pulmonary Fibrosis (IPF): More Needs to be Done. Lung 200, 673–675 (2022). https://doi.org/10.1007/s00408-022-00589-0
  3. Singh, N., Driessen, A. K., McGovern, A. E., Moe, A. A. K., Farrell, M. J., & Mazzone, S. B. (2020). Peripheral and central mechanisms of cough hypersensitivity. Journal of thoracic disease, 12(9), 5179–5193. https://doi.org/10.21037/jtd-2020-icc-007
  4. Hirons B, Rhatigan K, Wright L, et al.P212 Cough hypersensitivity features in interstitial lung disease, Thorax 2023;78:A239.
  5. Sgalla, G., Iovene, B., Calvello, M., Ori, M., Varone, F., & Richeldi, L. (2018). Idiopathic pulmonary fibrosis: pathogenesis and management. Respiratory research, 19(1), 32. https://doi.org/10.1186/s12931-018-0730-2
  6. Green, R., Baldwin, M., Pooley, N. et al. The burden of cough in idiopathic pulmonary fibrosis and other interstitial lung diseases: a systematic evidence synthesis. Respir Res 25, 325 (2024). https://doi.org/10.1186/s12931-024-02897-w
  7. Ando, A., Smallwood, D., McMahon, M., Irving, L., Mazzone, S. B., & Farrell, M. J. (2016). Neural correlates of cough hypersensitivity in humans: evidence for central sensitisation and dysfunctional inhibitory control. Thorax, 71(4), 323–329. https://doi.org/10.1136/thoraxjnl-2015-207425
  8. Ando, A., Smallwood, D., McMahon, M., Irving, L., Mazzone, S. B., & Farrell, M. J. (2016). Neural correlates of cough hypersensitivity in humans: evidence for central sensitisation and dysfunctional inhibitory control. Thorax, 71(4), 323–329. https://doi.org/10.1136/thoraxjnl-2015-207425
  9. Polverino M, Polverino F, Fasolino M, Andò F, Alfieri A, de Blasio F, et al. The cough reflex arc and its neurophysiology. Multidiscip Respir Med. 2012;7(1):5. doi: 10.1186/2049-6958-7-5
  10. Al-Biltagi M, Saber M, Tolba OA. Brainstem involvement and cough center. World J Crit Care Med. 2018;7(5):73–81. doi: 10.5492/wjccm.v7.i5.73
  11. Lim CY, Khan SW, Alsibai T, Sathiyamoorthy G. Examining cough’s role and relief strategies in interstitial lung disease. J Clin Med. 2025;14(1):291. doi: 10.3390/jcm14010291
  12. Hirons, B., Rhatigan, K., Wright, L., Kesavan, H., Mackay, E., Cho, P. S. P., Birring, S. S., & Myall, K. J. (2024). Patient Perception of Cough in Interstitial Lung Disease; Impact of Cough Hypersensitivity. Lung, 202(4), 425–430. https://doi.org/10.1007/s00408-024-00723-0

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