Dyspnea May Be Key to Distinguishing COVID-19 From Other Common Illnesses

MERS virus infection of lungs, conceptual illustration. MERS (Middle East respiratory syndrome) is a viral respiratory illness caused by the MERS-associated coronavirus (MERS-CoV). Formerly known as novel coronavirus, MERS was first identified in Saudi Arabia in 2012. Most people infected with MERS develop severe acute respiratory illness with symptoms of fever, cough, and shortness of breath.
Onset of dyspnea, particularly with precipitous drops in oxygen saturation especially with exertion, can help clinicians to more easily distinguish coronavirus disease 2019 from other common and treatable illnesses.

Onset of dyspnea, particularly with precipitous drops in oxygen saturation especially with exertion, can help clinicians to more easily distinguish coronavirus disease 2019 (COVID-19) from other common and treatable illnesses, according to study results published in the Mayo Clinic Proceedings.

In order to care for patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an urban, ambulatory clinic in Massachusetts, researchers focused on understanding typical presentation and early natural history of mild and moderate COVID-19 to guide patient care during the pandemic. Although this clinic had access to real-time reverse transcription polymerase chain reaction diagnostic testing for SARS-CoV-2, the delay in receiving the test results (4-5 days), made clinical management of the disease impractical. As such, researchers focused on trying to discern patterns, and observed that many moderate and severe cases of COVID-19 can be diagnosed from a detailed history and limited physical exam.

Researchers observed that though many patients will recover from their mild symptoms (ie, nasal congestion, cough without fever, sore throat, diarrhea, abdominal pain, headache, myalgias, back pain, anosmia, and fatigue), the onset of dyspnea, occurring between day 4 to 10 of onset of symptoms, may be the point at which COVID-19 can be discerned from other common illnesses. Older age, diabetes, cardiovascular disease, obesity, and hypertension were noted as risk factors for disease progression, but “the most useful factor to monitor [was] oxygen saturation which often drops precipitously with exertion,” stated the researchers.

To this end, researchers compared COVID-19 to various other treatable conditions, highlighting how dyspnea can assist clinicians in distinguishing the 2 diagnoses. Below is a list of key examples:

  • Legionella pneumonia vs COVID-19: Legionella pneumonia initially begins with fever and fatigue, followed by cough; dyspnea appears in cases in which the pneumonia progressed to become more severe. Conversely, in patients with COVID-19, cough and fever appear at the onset with dyspnea occurring a few days later, occasionally even after the fever has abated.
  • Pneumocystis jirovecii pneumonia vs COVID-19: Pneumocystis pneumonia is associated with a precipitous drop in oxygen saturation with exertion highly suggestive of SARS-CoV-2 infection,however, dyspnea develops insidiously over weeks in Pneumocystis pneumonia rather than days with COVID-19.
  • Postviral pneumonia vs COVID-19: Although cough and fatigue may be the initial symptoms in both, postviral pneumonia is associated with increasing fever and productive cough, whereas with COVID-19, there is worsening dyspnea without productive cough.
  • Uncomplicated influenza vs COVID-19: Unlike COVID-19, it would be uncommon to develop the onset of dyspnea 4 to 8 days after symptom onset in cases of uncomplicated influenza. In fact, dyspnea would likely improve gradually over the following days or weeks with an uncomplicated influenza infection.
  • Anxiety-induced dyspnea vs SARS-CoV-2-induced dyspnea: The distinguishing factor between these 2 is onset. In patients with anxiety-induced dyspnea, “dyspnea tends to occur at rest or when trying to fall asleep but does not become more pronounced when participating in daily activities,” whereas with SARS-CoV-2 infection, dyspnea is consistently worse with exertion.

Related Articles

In addition to distinguishing COVID-19 from other common and treatable illnesses, clinicians may want to “pay particular attention to identifying treatable etiologies of dyspnea including exacerbations of underlying pulmonary and cardiovascular disease and treat the exacerbation as [they] would have prior to the pandemic,” because the current treatment options for COVID-19 disease are limited, concluded the researchers.


Cohen PA, Hall L, Johns JN, Rapoport AB. The early natural history of SARS-CoV-2 infection: clinical observations from an urban, ambulatory COVID-19 clinic [published online April 20, 2020]. Mayo Clin Proc. doi:10.1016/j.mayocp.2020.04.010

This article originally appeared on Infectious Disease Advisor