Altered Level of Consciousness

CLINICAL DIAGNOSTIC MANUAL

Altered consciousness refers to a state in which an individual experiences a reduced ability to remain alert, aware, and oriented in their environment.

This condition can range from mild drowsiness to deep coma. Altered consciousness is a critical symptom that requires immediate evaluation to identify and treat the underlying cause.

The causes can be diverse, including metabolic, toxic, infectious, neurological, and traumatic factors. Detailed clinical assessment and the use of complementary tests are essential to determine the etiology and guide appropriate management.

Condition	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
Without brain damage	Drowsiness, lethargy, clouding of consciousness, stupor, coma	History of intoxication, hypoglycaemia, infections, metabolic disorders	Blood tests, toxicology, liver and kidney function tests
With minimal brain damage	Drowsiness, lethargy, slow responses, disorientation	History of mild trauma, infections, inflammatory conditions	CT or MRI showing minimal lesions or brain inflammation
With moderate brain damage	Lethargy, clouding of consciousness, responses to painful stimuli, severe confusion	History of moderate trauma, haemorrhages, CNS infections	CT or MRI showing haemorrhages, contusions, or moderate inflammation
With severe brain damage	Stupor, response only to vigorous stimuli, significant behavioural and consciousness disturbances	History of severe trauma, anoxia, large cerebral infarcts	CT or MRI showing large areas of brain damage, cerebral oedema
With very severe brain damage	Coma, unresponsive to any stimuli, signs of autonomic dysfunction	History of severe trauma, prolonged cardiac arrest, massive brain lesions	CT or MRI showing extensive brain lesions, EEG showing minimal or no activity