COVID-19 Pneumonia—the Lung Infection Caused by Getting COVID-19

COVID-19, the illness caused by the SARS-CoV-2 virus, doesn't hit everyone in exactly the same way. In general, most people infected with the virus will experience mild to moderate symptoms of headaches, fatigue, and coughing. Those people often fight the virus without any special treatment or hospitalization. For others, the virus takes on a more severe hold—and in some cases, that can include the development of pneumonia, a severe respiratory infection, sometimes requiring hospitalization or mechanical ventilation, and potentially even resulting in death.

Pneumonia caused by COVID-19 may also affect the body differently than other types of pneumonia. Here's what you need to know about COVID-19 pneumonia, including symptoms of the illness and treatment options that have typically been used during the pandemic.

The Link Between COVID-19 and Pneumonia

A quick refresher first: COVID-19 is a serious respiratory illness caused by the virus SARS-CoV-2. It can lead to a range of intense symptoms, including a cough, fever, trouble breathing, and loss of taste or smell, according to the Centers for Disease Control and Prevention (CDC).

And the CDC defined pneumonia as an infection of the tiny air sacs in the lungs (called alveoli) that can cause mild to severe illness.

Some patients with COVID-19 develop pneumonia—in fact, the World Health Organization (WHO) first called the virus novel coronavirus-infected pneumonia (NCIP) before shortening the name to COVID-19. The SARS-CoV-2 virus was also first identified in Wuhan, China, due to cases of "pneumonia of unknown etiology," or unknown cause, the WHO reported in January 2020.

It's not uncommon to develop pneumonia as the result of any virus, Raymond Casciari, MD, a pulmonologist at St. Joseph Hospital in Orange, California, told Health. In the case of COVID-19, the virus can damage your alveoli and cause fluid to build in your lungs as your body fights the infection, Dr. Casciari explained. That can also lead to the development of acute respiratory distress syndrome (ARDS). "The immune system starts attacking the lung itself, which results in ARDS," Dr. Casciari said. The American Lung Association defined ARDS as a serious form of respiratory failure that makes the alveoli fill with fluid.

COVID-19 Pneumonia vs. Other Pneumonia

COVID-19 pneumonia is different from other forms of pneumonia in that it doesn't necessarily cause people to get seriously ill right after they're infected. "You don't get sick immediately as you do with a lot of other viruses," Dr. Casciari said. "Then, in some people, the virus just explodes in the lungs, causing severe illness."

COVID-19 pneumonia also tends to be more severe than other forms of pneumonia, pulmonologist Marc Sala, MD, an assistant professor of medicine at Northwestern Medicine, told Health. "[Pneumonia caused by] SARS-CoV-2, when compared to other forms of pneumonia including influenza, has been shown to create an even more inflammatory type of infection that might be responsible for its severity and prolonged course in some people," Dr. Sala said.

A 2021 study published in the journal Nature found that COVID-19 infects several small areas of the lung at once, which is different from many forms of pneumonia that infect large areas of the lung. Then, COVID-19 takes over the lungs' own immune cells and uses them to spread across the lung over a period of days or weeks. As the infection spreads, it damages the lungs and causes fever, low blood pressure, and damage to the kidneys, brain, heart, and other organs. The researchers said that the severe complications of COVID-19 (compared to other types of pneumonia) could be because the virus causes a longer duration of illness.

A 2021 study published in Clinical Infectious Diseases analyzed CT scans and lab tests of patients with COVID-19 pneumonia compared to those with other types of pneumonia. Researchers discovered that people with COVID-19 pneumonia were more likely to have pneumonia that impacted both lungs and a "ground glass" appearance on scans—known more formally as "ground glass opacities"—which indicates abnormalities in the lungs.

Essentially, pneumonia associated with COVID-19 is a type of "very severe pneumonia," Nicola Hanania, MD, a pulmonologist at the Baylor College of Medicine, told Health.

Symptoms

The symptoms of COVID-19 pneumonia are basically the same as those for other forms of pneumonia, Dr. Casciari said. Those include:

• Cough
• Fever
• Shortness of breath
• Stabbing chest pain that gets worse when you breathe deeply or cough
• Loss of appetite
• Fatigue

People with COVID-19 pneumonia will often also have symptoms of COVID-19, Dr. Casciari said. According to the CDC, those include:

• Fever or chills
• Cough
• Shortness of breath or difficulty breathing
• Fatigue
• Muscle or body aches
• Headache
• New loss of taste or smell
• Sore throat
• Congestion or runny nose
• Nausea or vomiting
• Diarrhea

Risk Factors

Healthcare providers can't necessarily predict who will develop COVID-19 pneumonia. "It is not yet understood why some people get pneumonia, and others do not," Dr. Sala said. But, Dr. Sala added, some people are considered higher risk than others.

The CDC lists the following risk factors

• Obesity
• Diabetes
• Older age
• Underlying lung conditions

People who take immunosuppressant medication and pregnant women are also considered higher risk, Dr. Sala said.

Treatment

First and foremost, a healthcare professional will want to confirm that you do indeed have COVID-19, likely through a swab or sample of respiratory secretions that can detect the genetic material of the SARS-CoV-2 virus.

Once it's confirmed that you have COVID-19, a healthcare professional will then perform imaging tests like a computed tomography (CT) scan, which can help your provider see inside your lungs to look for any abnormalities. In addition to these scans and tests, your provider will also be able to gain more information for a diagnosis based on any symptoms you may be having.

As far as treatments go for pneumonia caused by COVID-19, that's where things get a little complicated. In general, there's no cure for viral forms of pneumonia, which is the classification COVID-19 pneumonia would fall under, Dr. Hanania said. However, according to the CDC, healthcare providers have typically been treating pneumonia from COVID-19 with the antiviral medication remdesivir and anti-inflammatory medications like the steroid dexamethasone.

In some cases, patients may be given monoclonal antibodies, which are laboratory-produced molecules that act as substitute antibodies that can restore, enhance, or mimic the immune system's attack on your cells, Dr. Casciari said. "They're not widely available, though, and they're not used often," Dr. Casciari added.

Overall, healthcare professionals say that if you develop symptoms of COVID-19 pneumonia, seek care immediately. "This can be very serious," Dr. Casciari said. According to the CDC, symptoms of COVID-19 that require emergency medical treatment include trouble breathing; persistent pain or pressure in the chest; and pale gray- or blue-colored skin, lips, or nail beds. Keep in mind, too, that this is not an exhaustive list—if you have any symptoms that are concerning to you, you should contact your provider.

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources.