Scientists have found an explanation for the lack of blood oxygenation in COVID-19

Happy hypoxia: scientists explain the lack of blood oxygenation in COVID-19

One of the concomitant characteristics of coronavirus, the scientists recognized the lack of blood oxygenation in many patients. It is called happy hypoxia. People who experience it have extremely low blood oxygen levels. The reason for this physiological phenomenon has not been explained yet. Low oxygen levels are noted in all severe cases of pneumonia without exception.

But despite this manifestation, they do not complain of shortness of breath or rapid breathing - these symptoms are traditionally present in hypoxemia caused by pneumonia. But they often show a sudden imbalance that can reach a critical level and lead to tragic consequences.


Typically, patients with hypoxemia complain of a lack of air, which can cause them to have difficulty breathing, which increases the oxygen consumption of the body. The mechanism depends on the carotid bodies.

They are located next to the carotid artery and are designed to record the drop in oxygen levels in the blood. Then they send signals to the brain to stimulate the respiratory center. The researchers from the Seville Institute of Biomedicine concluded that happy hypoxia during the COVID-19 can be caused by infection of this organ with the coronavirus.

The hypothesis attracted the attention of the scientific community and the experts conducted an experiment that showed a high presence of the ECA2 enzyme. This is a protein that the coronavirus uses to infect the human body in the carotid artery.


Based on this conclusion, the scientists suggest that infection of the carotid body in the earliest stages of the disease can change the ability to determine the level of oxygen in the blood and lead to an inability to control its fall.

Reference: “Is Carotid Body Infection Responsible for Silent Hypoxemia in COVID-19 Patients?” by Javier Villadiego, Reposo Ramírez-Lorca, Fernando Cala, José L Labandeira-García, Mariano Esteban, Juan J Toledo-Aral and José López-Barneo, 23 November 2020, Function. DOI: 10.1093/function/zqaa032