MB20.2

ICD-11 MMS 2026-01

Clouding of consciousness

Description

An impairment in the clarity of consciousness characterised by impaired ability to comprehend aspects of the environment or the self in relation to the environment, inattention, and abnormalities in thought processes, comprehension. It is typically accompanied by subjective experience of mental clouding described as feeling ‘foggy’. Clouding of consciousness is a common form of cognitive disturbance in Delirium, but it is not synonymous with Delirium because Delirium includes additional diagnostic requirements.

Index terms

  • Clouding of consciousness
  • Clouded state
  • brain fog
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  • mental fog
  • Subsyndromal delirium

Excludes

Exclusions from above levels

  • KC01 – newborn uremic coma
  • MB23.N – Psychomotor retardation
  • 19 – Certain conditions originating in the perinatal period
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  • JA66 – Clinical findings on antenatal screening of mother

Sibling codes

  • MB20.0 – Stupor
  • MB20.1 – Coma
  • MB20.Y – Other specified symptoms, signs or clinical findings involving consciousness

Foundation entity

Clouding of consciousness – http://id.who.int/icd/entity/1505501372

Part of: MB20: Symptoms, signs or clinical findings involving consciousness › 21: Symptoms, signs or clinical findings, not elsewhere classified