How COVID-19 Destroys the Lungs

Doctor with a stethoscope and a hologram of inflamed lungs.
COVID-19 primarily targets the lungs and respiratory tract in the human body. (Image: Александр Марко via Dreamstime)

There is no denying how the year 2020 changed life for billions of people, regardless of factors such as economic level, ethnicity, or religion. The COVID-19 pandemic changed the way people socialize, work, interact, and even buy things. While much has been said and written on the killer virus and its effects on the human body, it is time you learn precisely what happens in the lungs leading up to lethal outcomes. Even as the world is trying to return to normalcy, the mutating virus threatens to rise from the ashes like the proverbial phoenix, triggering the resumption of restrictions in many places.

COVID-19 is a member of the coronavirus family and it is closely related to severe acute respiratory syndrome (SARS). So it is natural that it primarily targets the lungs and respiratory tract in the human body. When you get infected with COVID-19, the primary reaction is mild flu-like symptoms, though some people can develop no symptoms worth noting.

In people with a compromised immune system, the lungs get affected badly and this may lead to a type of respiratory failure known as acute respiratory distress syndrome (ARDS) along with pneumonia. However, only a small percentage of affected persons succumb to death owing to lung failure. There is a link between getting infected with COVID-19 and developing ARDS. Some people develop ARDS and pneumonia almost simultaneously and that can prove to be fatal. 

Rendering of the coronavirus at a microscopic level.
There is a link between getting infected with COVID-19 and developing acute respiratory distress syndrome (ARDS). (Image: Geo000 via Dreamstime)

How COVID-19 impacts the lungs

It is important to know how COVID-19 impacts the lungs and jeopardizes the respiratory system in the human body. The virus damages the alveoli, or small air sacs, and the walls of the tract slowly. The accumulation of plasma protein on the alveolus wall results in a reduction in oxygen supply to the red blood cells. This leads to a gradual increase in breathing difficulty. The lack of oxygen then impairs organ functioning in the body.

While the immune system tries to destroy the virus and thwart its replication, this takes a backseat in people with weaker immunity levels. As the virus gradually damages the air sacs, it leads to an influx of liquid and that causes the onset of pneumonia. This affects the lungs’ working mechanism.

A number of studies have been carried out on the coronavirus and the findings have thrown light on its nuances, especially its impact on the lungs. A new German study is of special importance in this regard. Berlin’s Charite Hospital was where this study was performed by Leif-Erik Sander and a team. The team members say lung failure may not be an outcome of viral replication itself, but that it is more a result of the immune system response.

The study indicates that Sars-CoV-2 affects the scavenger cells in the human body and that leads to lung tissue scarring. This response means that the COVID-19 patients will need to be supplied with oxygen. A few may even need to undergo extracorporeal membrane oxygenation (ECMO), a process by which the patient’s blood is pumped outside their body into a machine that oxygenates it before returning it to their body.

A female hospital patient receiving oxygen while lying in bed.
COVID-19 patients who experience lung tissue scarring will need to be supplied with oxygen. (Image: Dragoscondrea via Dreamstime)

The study team thinks the lung tissue scarring caused by the virus is similar to what is seen with a condition like idiopathic pulmonary fibrosis. RWTH Aachen University’s Peter Boor said: “Almost all affected patients showed extensive tissue damage. The majority of the alveoli had been destroyed and the alveolar walls showed extensive thickening. We also found ubiquitous deposits of collagen, the main component of scar tissue.”

Lung failure takes around three weeks to develop after a person is infected with the virus and gets the first symptoms. Boor says: “This suggests that lung failure is not caused by the uncontrolled viral replication, but by secondary host responses, including those involving the immune system.” When the team analyzed the immune cells of people with severe COVID-19, they saw the lungs were laden with macrophages — immune cells used to discard pathogens. This proves the immune system was triggering a severe response.

The study finding shows there are strong resemblances between idiopathic pulmonary fibrosis and COVID-19. The scarring found in COVID-19 patients can be repaired, which is not possible in cases of idiopathic pulmonary fibrosis. With treatment done at the right time, partial repairing is possible, say the doctors.

Follow us on Twitter, Facebook, or Pinterest

RECOMMENDATIONS FOR YOU