This article focuses of the cognitive components of long COVID, also known as ‘brain fog’. It complements a previous How to Treat on post-infective fatigue syndrome and long COVID (see resources).¹

There is evidence that long COVID is another example of post-viral syndrome, a well-recognised phenomenon.² In this article the term post-viral syndrome is used synonymously with post-infective fatigue syndrome.¹ 

This illustrative and encompassing colloquial term describes the subjective cognitive symptoms associated with post-viral syndrome (PVS). It reflects a sense of feeling hazy, fuzzy and not sharp, especially when there is a need to concentrate and focus attention.

This is a common human experience. It may occur during an acute influenza-like illness, or when jet-lagged, or sleep deprived. This experience is usually transient and improves rapidly.