Many people who contract COVID-19 have mild to moderate symptoms, but some can have more severe complications.
COVID-19, the illness caused by the SARS-CoV-2 virus, hits everyone differently. In general, most people infected with the virus will experience mild to moderate symptoms—headaches, fatigue, coughing. Those people often fight the virus off 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 complication of the virus, sometimes resulting in hospitalization, ventilation, or even 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.
What’s 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). Pneumonia is an infection of the tiny air sacs in the lungs (called alveoli) that can cause mild to severe illness in people, the CDC says.
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, tells 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, he explains. That can also lead to the development of acute respiratory distress syndrome (ARDS), which is a serious form of respiratory failure that makes the alveoli fill with fluid. “The immune system starts attacking the lung itself, which results in ARDS,” Dr. Casciari says.
How is COVID-19 pneumonia different from other types of 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 like you do with a lot of other viruses,” Dr. Casciari says. “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, tells 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,” he says.
A 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 in the study that the severe complications of COVID-19 (compared to other types of pneumonia) could be because the virus causes a longer illness.
Another study, published in the journal 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, tells Health.
What are the symptoms of COVID-19 pneumonia?
The symptoms of COVID-19 pneumonia are basically the same as they are for other forms of pneumonia, Dr. Casciari says. 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 says. 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
Who is more likely to get COVID-19 pneumonia?
Doctors 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 says. But, he adds, some people are considered higher risk than others, including people with the following health conditions or risk factors.
- Obesity
- Diabetes
- Older age
- Underlying lung conditions
People who take immunosuppressant medication and pregnant women are also considered higher risk, Dr. Sala says.