What is Chronic Cough?

Chronic cough is a persistent cough that lingers for more than 8-12 weeks/over 2 months (1;2). Chronic cough is often triggered by a viral illness such as influenza or may be associated with conditions such as asthma, sinusitis or post-nasal drip, and gastroesophageal reflux (GERD).  

When the cough does not go away despite treatment for these conditions, it is classified as a “Refractory Chronic Cough” (acronym RCC).  
When there does not appear to be any underlying condition it is described as “Idiopathic Chronic Cough” (3).  Many people with this condition suffer from hypersensitivity of the upper airway to irritants such as strong smells, dust, or changes in temperature.  Other triggers for cough may include talking or laughing. 

What are the Symptoms of Chronic Cough?

Possible Effects of Living with Chronic Cough:

A chronic cough can seriously impair people’s quality of life.  Paroxyms (fits) of cough can be physically fatiguing, and may get worse with sleep deprivation leading to severe fatigue.  Chronic cough may cause people avoid public gatherings, or transportation leading to social isolation and depression. (4-7)  

Severe coughing may also take a toll on the body including rib fractures, urinary incontinence, and syncope (passing out). (7-9)

A man sitting on a couch, sneezing into his elbow while holding a mug in his other hand. He is wearing a denim jacket and appears to be at home.

How is Chronic Cough diagnosed and tracked?

Discussing your symptoms with a healthcare provider is often the best way to diagnose chronic cough, then together you can look for its cause using various tests. 

  • Diagnostic testing: 
    • Lung imaging
      • X-rays or CT scans help diagnose some of the causes of chronic cough 
    • Lab work 
      • Identifies signs of inflammation or allergy in your blood or sputum (phlegm) 
    • Lung function tests
      • Identify some diseases like asthma, or COPD 
      • The most common test is spirometry, often used to diagnose COPD and asthma, but you may also be sent for lung volume test or diffusing capacity test.
    • Tests using a scope (a tube)
      In cases where your doctor is unable to determine the cause of your cough, they may order special scope tests such as rhinoscopy and bronchoscopy.

      This will involve inserting a thin tube with a light and lens in the nose or mouth. A biopsy can be taken from these places to check for abnormalities.
      • Rhinoscopy involves using a rhinoscope to view the sinuses, nasal passageways, and upper airway.
      • Bronchoscopy uses a bronchoscope to view the airways and lungs. 
    • Allergy skin testing
      • Can help identify your coughing triggers
  • Cough monitoring to track chronic cough 
    • Devices and/or apps developed as tools that can help you, your caregiver and healthcare provider manage your cough and understand the best treatment for you. By monitoring changes in cough frequency and quality, treatments can be adjusted to best fit your needs. (21;22)

What Treatments are Available for Managing Chronic Cough?

  • Medical treatment
    • Treating the underlying cause (if known) will improve or eliminate chronic cough: a “cure”
    • There is no medication approved for chronic cough related to unknown causes (idiopathic cough). 
    • Your healthcare provider may recommend over-the-counter cough suppressants, but they are not recommended for chronic cough as there is little evidence that they work.
    • Opiates: Current treatments for chronic cough involve opiates such as codeine, morphine, and diamorphine. Opiates must be taken only when prescribed by your physician and in the right dosage, as directed.
    • Gefapixant: A P2X3 receptor antagonist that works by binding to receptors present in the lining of sensory nerve fibers in the airways and reducing their activation. It is currently approved in Japan, Switzerland, and the European Union for the treatment of adults with refractory or unexplained chronic cough. At this time, it is not approved in the US, but research is ongoing to support review by the US Food and Drug Administration (FDA). (24)
  • Airway Clearance Techniques and devices help clear out the mucus or phlegm 
  • Home remedies may include drinking enough water and staying well hydrated, using air humidifiers for dry cough, mint lozenges, or tea with honey that may ease symptoms. (24)
  • Lower your risks: reducing your exposure to smoke, pollution, and toxic fumes. Speak to your healthcare provider about quitting smoking or joining a support group.

Who Treats Chronic Cough?

Most people experiencing chronic persistent cough are diagnosed by a family healthcare provider, pediatrician (children) or general practitioner in their community. Those with co-morbidities are treated by specialists: pulmonologists, allergists, and/or gastroenterologists.

What are the Causes or Risk Factors for Chronic Cough?

There are many probable causes for chronic cough, including different chronic  medical conditions that are often called co-morbidities like asthma, gastroesophageal reflux (13), allergy or post nasal drip (14). When the cause is not known, chronic persistent cough is called idiopathic. Treatment depends on the type of chronic cough you have.

Risk factors for Chronic Cough:

These risks can be controlled by avoiding exposure

  • Smoking
    • People having smoked at least 100 cigarettes in their lifetime have a doubled or tripled risk of chronic cough compared with non-smokers. (17).
  • Use of medications called ACE inhibitors
    • Drugs used to treat high blood pressure. If you are experiencing chronic cough and take this medication, your healthcare provider may prescribe another medicine for you. 
  • Environment/Air pollutants 
    • Secondhand smoke (living or spending time with people who smoke) (18).
    • Living or working in certain places can cause more exposure to airborne foreign objects or particles, and toxic chemicals. (19;20).

What is the Prevalence of Chronic Cough around the World?

Chronic cough is a worldwide issue. Recent studies show it is a more common diagnosis in certain regions (Australia, NZ report >20% incidence while North America and Europe range 10-15% of the population) with less reports in Asia, Latin America and Africe. The reasons for this variability are unclear. It may be due to under-reporting or patients being diagnosed with other conditions such as asthma, or allergy. 

However, even though different regions define chronic cough differntly, the relationships between region and chronic cough prevalence seems consistent in many studies. It is possible that there are environmental or genetic factors influencing them. (10; 11; 12)

“For more information on global impact of chronic cough click here: “The global epidemiology of chronic cough in adults” 

Is there Research on Future Treatments for Chronic Cough?

  • There are several new drugs in clinical trials for chronic cough.
  • GAAPP aims to help support research that will find safe treatments for idiopathic cough (of unknown causes, also called refractory cough when it does not respond to treatments.
  • To find a clinical trial recruiting in your area, you may search the trial registry clinicaltrials.gov using the term “Chronic Cough” or “Refractory Cough”, adding your location (country) and selecting “Recruiting and not yet recruiting studies”  

References

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  2. Irwin RS, French CL, Chang AB, Altman KW, CHEST Expert Cough Panel*. Classification of cough as a symptom in adults and management algorithms: Chest guideline and expert panel report. Chest. January 2018. Accessed March 8, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6689094/
  3. McGarvey LP. Does idiopathic cough exist?. Lung. 2008;186 Suppl 1:S78-S81. doi:10.1007/s00408-007-9048-4 Accessed March 8, 2024. https://pubmed.ncbi.nlm.nih.gov/18008103/. .
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  21. Siwicki B. How care for cough – one of the top medical complaints – can benefit from RPM and ai. Healthcare IT News. October 17, 2023. Accessed March 8, 2024. https://www.healthcareitnews.com/news/how-care-cough-one-top-medical-complaints-can-benefit-rpm-and-ai
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Content reviewed by a member of GAAPP Clinical and Scientific Advisory Panel