Clouding of Consciousness

The clouding of consciousness, defined as ‘potentially reversible global impairment of cognitive processes’ (Lipowski, 1967), represents the lesser stages of impairment of consciousness Opens in new window, with deterioration in thinking, attention, perception and memory and, usually, drowsiness Opens in new window and reduced awareness of the environment.

Clouding of consciousness, which can occur in susceptible individuals in response to certain types of psychological stress without a specific organic illness or state influencing brain function, has also been defined as,

a state of reduced wakefulness in which periods of excitability and irritability often alternate with periods of drowsiness.

Drowsiness Opens in new window as a descriptive term simply means diminished alertness and attention that is not under the patient’s control.

In clouding of consciousness, psychological symptoms are nonspecific, so that an individual with cognitive impairment may show dysphoric affect, anxiety Opens in new window, or any other symptom of psychiatric illness, such as projection, paranoia, and hysterical or schizophrenic symptoms.

In states of clouded consciousness, the patient appears dazed and “out of it,” and there is severe misperception of the nature and significance of his situation. It is often necessary to shout at him repeatedly or to shake him in order to obtain and keep his attention.

Little effort is made by the patient to follow directions and, if he is ambulatory, he may blunder into dangerous circumstances. All motor functions are grossly impaired. Orientation for time and place Opens in new window are disturbed, and there is marked impairment of memory Opens in new window and intelligence Opens in new window.

Patients may shift back and forth between the various levels of consciousness within brief time periods. This is particularly true of brain impairments produced by acute illnesses.

There are important differences between the reduced wakefulness before falling asleep and clouding in an organic state (Lipowski, 1967). Although the patient’s awareness is clouded, he may be agitated and excitable rather than drowsy.

Clouding may be seen in a wide variety of acute organic conditions, including drug and alcohol intoxication, head injury, meningeal irritation caused by infection and so on.

    Adapted from:
  1. Sims' Symptoms in the Mind: An Introduction to Descriptive Psychopathology By Femi Oyebode
  2. Extraordinary Disorders of Human Behavior By Claude T. H. Friedmann, Robert A. Faguet