Table of ContentsView AllTable of ContentsNormal LOCAltered LOCComa Classifications
Table of ContentsView All
View All
Table of Contents
Normal LOC
Altered LOC
Coma Classifications
“Level of consciousness” (LOC) is a medical term used to describe how awake, alert, and aware you are. It also refers to how well you respond to attempts to get your attention. A person with an altered level of consciousness may have decreased cognitive function or be difficult to arouse.
A variety of medical conditions and drugs can affect your level of consciousness, from having dementia or lethargy to being in a coma. Sometimes impaired consciousness is reversible, while other times it is not.
This article covers normal and altered states of consciousness as well as coma classifications.
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What Is Consciousness?
Medical definitions say a normal LOC means a person is either awake or can be readily awakened from normal sleep. Terms include:
Sleeping is not considered unconsciousness if waking up would result in normal consciousness Between consciousness and unconsciousness there are several altered levels, each with its own definition.
Altered Level of Consciousness
Altered or abnormal levels of consciousness are states in which you either have decreased cognitive function or cannot be easily aroused.
Most medical conditions affect the brain and impair consciousness when they become serious or life-threatening. An altered LOC usually signals a serious medical problem.
Are You at Risk of Altered Level of Consciousness?If you are at risk for altered LOC, be sure to have the proper medical precautions in place. For example, wear amedical alert braceletor download a phone app that lists your diagnoses, medications, and emergency contacts. Some apps can be accessed even when your phone is locked. You may also want to designate a healthcare proxy to speak for you if you are unable.
Are You at Risk of Altered Level of Consciousness?
If you are at risk for altered LOC, be sure to have the proper medical precautions in place. For example, wear amedical alert braceletor download a phone app that lists your diagnoses, medications, and emergency contacts. Some apps can be accessed even when your phone is locked. You may also want to designate a healthcare proxy to speak for you if you are unable.
Often, an altered LOC can deteriorate rapidly from one stage to the next. They require timely diagnosis and prompt treatment.
Confusion
Confusion describes disorientation that makes it difficult to:
Causes include:
Delirium
Delirium is a term for an acute confused state. It involves impaired cognition (thought processes) and may include:
Causes can include:
Delirium Risks and Effects
Lethargy and Somnolence
Lethargyandsomnolence(sleepiness) involve:
A lethargic person may need a gentle touch or verbal stimulation before they will respond.
Obtundation
Obtundationis reduced alertness with:
Stupor
Someone in a stupor responds minimally to vigorous stimulation, such as a pinched toe or light in the eyes.
Coma
A person in acomadoes not respond to any stimuli. Their pupils may not react to light, and they may not have a gag reflex.
What Is Myxedema Coma?
The causes of altered LOC may overlap. For example, the early stages of brain edema or organ failure can cause confusion but then advance rapidly through lethargy, obtundation, stupor, and coma.
Levels of Consciousness Assessment Scale
Levels of consciousness can be subdivided into levels that further clarify your degree of unresponsiveness. That helps improve communication among healthcare providers as well as aiding in research.
Several systems have been developed to standardize these classifications. The most common classification systems are:
Nursing Assessment of LOCNurses may evaluate LOC based on the following categories:Alert: Opens eyes spontaneously, looks at the speaker when spoken to in a normal voice, responds appropriately to stimuli, and movements are purposefulLethargic: Appears drowsy but opens eyes to loud verbal stimuli. Looks at the speaker and responds to questions before falling back to sleep.Obtundation: Opens eyes with tactile stimuli and looks to the source but responds slowly and may be confusedStupor: Awakens only after a painful stimulus is applied (e.g., applying pressure to the nailbed). Verbal responses are slow or absent. Will fall into an unresponsive state when the stimulus stops.Coma: Unarouseable and eyes remain closed. There are no purposeful responses to internal or external stimuli. However, nonpurposeful responses to painful stimuli and brain stem reflexes may still be present.
Nursing Assessment of LOC
Nurses may evaluate LOC based on the following categories:Alert: Opens eyes spontaneously, looks at the speaker when spoken to in a normal voice, responds appropriately to stimuli, and movements are purposefulLethargic: Appears drowsy but opens eyes to loud verbal stimuli. Looks at the speaker and responds to questions before falling back to sleep.Obtundation: Opens eyes with tactile stimuli and looks to the source but responds slowly and may be confusedStupor: Awakens only after a painful stimulus is applied (e.g., applying pressure to the nailbed). Verbal responses are slow or absent. Will fall into an unresponsive state when the stimulus stops.Coma: Unarouseable and eyes remain closed. There are no purposeful responses to internal or external stimuli. However, nonpurposeful responses to painful stimuli and brain stem reflexes may still be present.
Nurses may evaluate LOC based on the following categories:
Summary
Levels of consciousness range from normal alertness and attention to gradations of altered states, including confusion, delirium, stupor, and coma.
The same conditions may produce mild to severe states of altered LOC. Sometimes, there may be a rapid progression from a mild to a high stage.
Coma scales can help describe the exact level of consciousness.
Best Medical Alert Systems
14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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