How Is My COVID-19 Classified as Mild, Moderate, or Severe?

Physician review of medical literature regarding classification of COVID-19 severity.

Julian Willett, MD
Jan 23 · 5 min read
Photo by Daniel Schludi on Unsplash

This morning I learned that Larry King died, perhaps due to COVID-19 given that he was hospitalized for disease-related management. The sad reality of the current pandemic is that there are few treatments. We have a great way to prevent infections with vaccines (read my review here addressing what to expect from them, including side effects), but the high mortality of the infection persists.

Given the breadth of even limited treatment of COVID-19, which is dependent on disease severity, I will be breaking up a review of COVID-19 treatment and classification of COVID-19 into separate articles.

This article will review the classification of COVID-19 severity, as published by the World Health Organization¹. I located this source using the evidence-based medical database, Dynamed².

Photo by Thom Holmes on Unsplash

Mild disease is when a patient most likely does not have issues keeping their body oxygenated and lack pneumonia¹. Roughly 40% of people who develop COVID-19 have mild disease¹. They can still have symptoms¹. A patient is said to keep their body oxygenated well when they, for example, do not require any supplemental oxygen for comfort or breathing difficulty.

While a person’s blood oxygen level can be roughly determined using those finger blood oxygen monitors, ultimately a patient’s overall clinical picture as determined by a licensed healthcare provider is required to determine the best course of action and determine the severity of a patient’s disease. A pulse oximeter by itself is not enough to make a diagnosis.

Determination of whether a patient has pneumonia can be determined by a licensed healthcare provider’s consultation with a physical exam. Sometimes getting an x-ray or CT-scan of your chest is required for the diagnosis, but not always.

Medical procedures, including imaging, are done when it would change how your disease would be managed. If your overall clinical picture is consistent with a given disease as determined by a provider, imaging may not add any additional information so it would not be done.

Photo by United Nations COVID-19 Response on Unsplash

Moderate disease is when a patient has evidence of pneumonia from the virus but does not have evidence that their body is having a hard time keeping itself oxygenated¹. This means that these individuals do not require supplemental oxygen¹.

Roughly 40% of patients with COVID-19 will have moderate disease¹. Signs of symptomatic pneumonia can include more rapid breathing, feeling short of breath, coughing, and fever¹. Imaging can also support the diagnosis if it is deemed appropriate for an individual’s clinical picture¹.

More rapid breathing can in most cases only be effectively evaluated by a medical professional because individuals who try to measure their rate of breathing tend to change it when they are aware of what is being checked even if they try to breathe as they would normally under the given circumstances.

Photo by Bret Kavanaugh on Unsplash

Severe disease is characterized by evidence of pneumonia that is more severe as suggested by clinical measures that would indicate that the body is having a hard time keeping everything oxygenated¹. Around 15% of all COVID-19 patients develop severe disease. Clinical evidence that suggests issues with oxygenation includes someone feeling short of breath to the point where it is determined by a provider that they need supplemental oxygen¹.

Around 5% of COVID-19 patients develop a critical disease. It can be characterized by severe lung damage (acute respiratory distress syndrome) or shock¹. The severe lung damage in critical disease is often what would lead to someone requiring a machine to breathe for them. Shock is where parts of the body start to die or shut down because organs do not have enough access to oxygen. Both of these would typically require ICU-level care.

Fortunately, most individuals have mild/moderate disease, which means they are less likely to succumb to their illness. The disease can progress. Individuals can have mild disease one day and then, for whatever reason, it can get worse and someone could progress into severe COVID-19.

This article demonstrates the prudence in doing everything possible to avoid becoming infected COVID-19 in the first place, which includes wearing masks, social distancing, and practicing appropriate hygiene. COVID-19 does not equate with certain doom, people do get better, even if it is sometimes accompanied by continued symptoms weeks/months afterward. The minority of individuals who develop COVID-19 develop disease so severe that they require ICU care.

This minority is significant enough that we all need to put conscious effort into keeping ourselves safe in this uncertain time. We can get through this. It will just take time and tolerating the unpleasantness that is wearing masks, having limited contact with our friends and family, and having limited things to do outside our homes.

Consider the sacrifices during this current time as an investment towards having an even more enjoyable time when we can relax, as determined by public health departments. If you have any questions or concerns about COVID-19, contact your doctor or refer to your local public health department and they can provide information to help you take your best step forward.

This article is meant for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.


Make informed choices about your Health

Julian Willett, MD

Written by

Loving husband. Physician scientist who enjoys spreading his knowledge with the world whether related to medicine, technology, or science.


A Medika Life Publication for the Medical Community

Julian Willett, MD

Written by

Loving husband. Physician scientist who enjoys spreading his knowledge with the world whether related to medicine, technology, or science.


A Medika Life Publication for the Medical Community

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