Silent Mucus Plugs in COPD: Emily S. Wan, MD

Mucus plugging is common in chronic obstructive pulmonary disease (COPD), often occurs without cough or sputum, and may signal more severe disease, according to Emily Wan, MD, assistant professor of medicine at Harvard Medical School, at the 2026 Global Initiative for Chronic Obstructive Lung Disease (GOLD) International COPD Conference,

In an interview with The American Journal of Managed Care^®, Wan discussed how often mucus plugs appear and go unnoticed by patients, how clinicians can detect them and respond, and what evidence would make them part of COPD management.

How Common Silent Mucus Plugs Are

“Mucus plugging is actually very common,” Wan said, including outside the setting of an acute illness. Across large cohort studies, prevalence ranges from 25% to almost 80%, depending on the cohort. Data also suggest that about one-third of patients have what Wan called silent mucus plugs, meaning plugs that are not associated with cough or sputum.

Wan said mucus plugs and symptoms appear to capture different aspects of COPD. Spirometry measures only airflow limitation, while symptoms reflect what the patient experiences. “I’ve had people who have terrible spirometry, but actually are very active and functional,” Wan said.

How to Detect and Respond to Mucus Plugs

Mucus plugs tend to be associated with worse disease, Wan said. When plugs are visible on a CT scan, Wan becomes more alert to the possibility that a patient has more symptoms and is more likely to ask about them.

However, detection is still difficult, according to Wan. Identifying plugs relies on expert readers who have to be trained, so Wan advised clinicians to work with their radiology team and have radiologists note any plugs in the report to alert the treating physician. Beyond awareness that a patient may have more severe disease, Wan said, clinicians may not need to act directly on a mucus plug unless it is causing immediate obstruction.

What Would Make Mucus a Treatment Target

For mucus plugging to serve as a meaningful clinical signal, “it needs to show that it is dynamic, that it reflects disease status,” Wan said. There would be additional excitement if it can be shown that plugs are part of the disease process itself.

Wan raised the example of whether mucus plugs act as a nidus of infection that triggers an exacerbation. If so, Wan said, that would make the case for mucus plugs to become part of the algorithm for treating and managing COPD.