Many who became infected with the coronavirus and survived may not be out of the woods just yet.

A special clinic at Northwestern Memorial Hospital in Chicago published a study focused on long-term neurological symptoms in people who were never sick enough to need hospitalization for COVID-19, finding long-haulers experience prominent “brain fog” and fatigue that is affecting their cognition and quality of life.

Brain fog has been categorized as forgetfulness, confusion and difficulty focusing.

“Even though someone was asymptomatic, they may actually have had a period of low oxygen to the brain and not realized it," says Dr. Helen Valsamis, the chief of neurology at NYC Health + Hospitals/Kings County.

She advises those experiencing these symptoms avoid alcohol or other substances that can impair brain function, to rest when needed and to exercise.

Valsamis says other cognitive rehabilitation could help recovery too, such as listening to music or reading.

She recommends anyone experiencing brain fog to see their primary care physician.