The "brain fog" of long COVID might be due to impaired lung function following a person's infection, a new study says.

Lower rates of gas exchange in the lungs may contribute to impaired cognitive function ("brain fog") tied to long COVID, according to a small study to be presented at next week's Radiological Society of North America's (RSNA's) annual meeting in Chicago.

Study senior author Dr. Sean Fain said: “If these findings can be generalized to the long Covid population, the study suggests that there may be a causative relationship between cognitive dysfunction and lung dysfunction, suggesting a potential treatment strategy using methods that target improved gas exchange.”

In patients with long COVID, lower pulmonary gas exchange may be associated with impaired cognitive function, according to a study being