This lesson will go over several different levels of consciousness and define: consciousness, unconsciousness, confusion, delirium, lethargy, obtundation, syncope, stupor, coma and persistent vegetative state.


Levels of Consciousness


Whether due to trauma from a car accident or a disease, such as unmanaged diabetes, if you work in the medical field, you'll come across scenarios where people will have altered levels of consciousness. A level of consciousness (LOC) is the degree of a patient's cognitive function.


Consciousness is the state of being awake, aware, alert and responsive, while unconsciousness is the state of being unaware and unresponsive to stimuli. But in between consciousness and unconsciousness, there are many other levels of consciousness. Confusion, Delirium, Lethargy & Obtundation.


 Let's start with confusion. Confusion is a disturbed orientation with respect to time, place or person. It's a state of mind that causes disorientation, bewilderment, poor decision making and difficulty following commands. Confusion can come from drug abuse, a fever or even sleep deprivation, among other reasons. Confusion is a part of delirium, a sudden and typically fluctuating and reversible condition marked by hyper-alertness one moment and confusion, sluggishness and disorientation the next.


Delirium can result from everything from intoxication to surgery, especially in elderly patients. Another LOC is lethargy, a level of consciousness marked by drowsiness, listlessness, apathy and a small reduction in alertness. As with any altered LOC, lethargy has many potential causes, including anemia, an underactive thyroid and cancer. More serious than lethargy is obtundation, a moderate reduction in alertness. The term obtundation is not very precise, as it is sometimes defined as greatly reduced levels of consciousness. Obtundation can result from poisonings, seizure disorders and more.


Syncope, Stupor, Coma & Persistent Vegetative State Perhaps you know of someone who has fainted, for any number of reasons. Fainting is more formally called syncope, and as you probably know, it is a brief loss of consciousness. Fainting can occur due to cardiovascular problems or strong emotions, like being scared out of your mind.


Definitely more severe than this is stupor, a deep level of impaired consciousness where only vigorous repeated stimuli arise the individual for a brief moment.


According to Freud, there are three main Levels of Consciousness:


  1. Conscious Mind: what we are aware of in everyday life
  2. Preconscious Mind: where we store information we have learned
  3. Unconscious Mind: where we keep information that is not yet readily available to us (unpleasant memories)


Author: Joshua Martin Q. Serrano