Understanding the Difference Between Asthma and Vocal Cord Dysfunction

Difficulty breathing, coughing and wheezing...

At first glance, you may be thinking of asthma. However, when the above symptoms are broken down, they also align very closely with a lesser known condition: vocal cord dysfunction. Due to the overlap of symptoms between these two conditions, vocal cord dysfunction and asthma can often be confused. 

Vocal Cord Dysfunction

Vocal cord dysfunction (VCD), also known as or paradoxical vocal fold movement (PVFM), is the atypical closure of the vocal cords when breathing. Normally, our vocal cords are open upon inhalation to allow air flow into the lungs. However, VCD occurs when the vocal cord muscles contract during inhalation, causing a narrowing of the larynx. This contraction blocks the passage of air into the lungs. Like asthma, VCD can be triggered by irritants, exercise, and upper respiratory infections. VCD can also be triggered by post nasal drip and reflux. The symptoms of vocal cord dysfunction include: shortness of breath, trouble upon inhalation, coughing, throat clearing, throat tightness and wheezing. Diagnosing VCD can be challenging but begins with history and physical exam, followed by spirometry and laryngoscopy. Treatments for VCD include deep breathing techniques and speech therapy. 

Asthma

Asthma is the result of a strong immune response that causes the narrowing and swelling of the airways in the lungs. This narrowing restricts the airflow in and out of the lungs, resulting in difficulty breathing. Asthma can be triggered by irritants, allergens, exertion and upper respiratory infections. The symptoms of asthma include chest tightness, shortness of breath, wheezing and coughing. Treatments of asthma include short-acting medications and long-acting medications. The short acting medications can be used to prevent or relieve symptoms during an asthma attack. While the long acting medications function to control asthma symptoms long term by preventing the narrowing and swelling of the airways. 

Identifying Key Differences Between Asthma and VCD 

There are a number of key clinical differences between these two conditions that may help during the diagnosis process. Those with VCD are more likely to report shortness of breath and wheezing upon inhalation versus exhalation. The sensation is often described as if one was breathing through a straw. In contrast, those with asthma tend to have more difficulty breathing during exhalation compared to inhalation. Secondly, the sensation of tightness originates from a different location in each condition. Those with VCD report throat tightness, while those with asthma report chest tightness. Finally, in those with VCD, asthma medications do not ease symptoms. Many times VCD is looked at as the probable diagnosis after asthma medications have been tried and failed.

If you have any concerns or are experiencing the above symptoms, please consult a physician who can properly diagnose and treat you.

Isabel Welsh, Medical Intern