Clouding of consciousness

Clouding of consciousness, also known as brain fog or mental fog, is a term used in conventional medicine denoting an abnormality in the regulation of the overall level of consciousness that is mild and less severe than a delirium. The sufferer experiences a subjective sensation of mental clouding described as feeling "foggy".

Background

The term clouding of consciousness has always denoted the main pathogenetic feature of delirium since Greiner first pioneered the term (Verdunkelung des Bewusstseins) in 1817.The Diagnostic and Statistical Manual of Mental Disorders (DSM) has historically used the term in its definition of delirium. Recently the DSM has replaced “clouding” with “disturbance” but it is still the same thing . However, there appears to be a trend among many doctors to now redefine clouding of consciousness to be less severe than delirium on a spectrum of abnormal consciousness. In this case, it can be said that clouding of consciousness is synonymous with subsyndromal delirium.