In the cohort study, published in Mayo Proceedings, researchers looked at the charts of 108 patients suffering from long-haul COVID who came to the care clinic from Jan.

Related [May 12, 2021]: Mayo Clinic study details 'severe negative impacts' of long COVID.

The exact number of people who survive COVID, yet deal with sometimes-debilitating long COVID symptoms long into the future, is not totally clear yet.

One Penn State study from October estimated about half of all COVID survivors will deal with some long-haul COVID symptoms in the six months after recovering from their initial infection.

According to the study, one in five COVID survivors had trouble moving around afterward; one in four had trouble concentrating, often called "brain fog"; and nearly 60% had a "chest imaging abnormality" afterward.

Related: COVID vaccines are more protective than natural immunity, study finds.

The Mayo Clinic researchers said they hope insights from the study may help us better understand the causes of, and treatment for, long COVID.