COVID-19, the disease caused by the new coronavirus, can cause lung complications such as pneumonia and, in the most severe cases, acute respiratory distress syndrome, or ARDS. Sepsis, another possible complication of COVID-19, can also cause lasting harm to the lungs and other organs.
In pneumonia, the lungs become filled with fluid and inflamed, leading to breathing difficulties. For some people, breathing problems can become severe enough to require treatment at the hospital with oxygen or even a ventilator.
The pneumonia that COVID-19 causes tends to take hold in both lungs. Air sacs in the lungs fill with fluid, limiting their ability to take in oxygen and causing shortness of breath, cough and other symptoms.
While most people recover from pneumonia without any lasting lung damage, the pneumonia associated with COVID-19 may be severe. Even after the disease has passed, lung injury may result in breathing difficulties that might take months to improve.
Acute Respiratory Distress Syndrome (ARDS)
As COVID-19 pneumonia progresses, more of the air sacs become filled with fluid leaking from the tiny blood vessels in the lungs. Eventually, shortness of breath sets in, and can lead to acute respiratory distress syndrome (ARDS), a form of lung failure. Patients with ARDS are often unable to breath on their own and may require ventilator support to help circulate oxygen in the body.
Whether it occurs at home or at the hospital, ARDS can be fatal. People who survive ARDS and recover from COVID-19 may have lasting pulmonary scarring.
Another possible complication of a severe case of COVID-19 is sepsis. Sepsis occurs when an infection reaches, and spreads through, the bloodstream, causing tissue damage everywhere it goes.
“Lungs, heart and other body systems work together like instruments in an orchestra,” Galiatsatos says. “In sepsis, the cooperation between the organs falls apart. Entire organ systems can start to shut down, one after another, including the lungs and heart.”
Sepsis, even when survived, can leave a patient with lasting damage to the lungs and other organs.
Galiatsatos notes that when a person has COVID-19, the immune system is working hard to fight the invader. This can leave the body more vulnerable to infection with another bacterium or virus on top of the COVID-19 — a superinfection. More infection can result in additional lung damage.