COVID-19 damages lung blood vessels

photo of blood clots

New NHLBI-funded research reveals that coronavirus disease (COVID-19) damages blood vessels in the lungs and triggers clots, which helps explain how it impairs breathing and can lead to death in severe cases.

Researchers knew that people who died from COVID-19 had widespread lung inflammation or acute respiratory distress syndrome (ARDS). But it wasn’t clear how the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, triggered that condition. To shed some light on this, an international team of researchers report in The New England Journal of Medicine that they compared seven lungs from people who died from COVID-19 with lungs from seven people who died from ARDS caused by the flu.

The COVID-19 lungs had substantially more damage to the lining of blood vessels than the flu lungs. The lungs also had widespread blood clotting that was triggered by the blood vessel damage.

The researchers also found substantial growth of new blood vessels in the COVID-19 lungs, which they think was triggered by the body’s attempt to heal and repair the lung damage.