Signs and Symptoms of Alcohol Intoxication
Alcohol intoxication presents with a predictable progression of neurologic, behavioral, and autonomic symptoms that correlate with blood alcohol concentration, ranging from initial dysphoria and disinhibition to potentially fatal respiratory depression and coma. 1
Early Signs (Mild Intoxication)
- Behavioral changes including dysphoria, disinhibition, and emotional lability are the initial manifestations 2, 1
- Cognitive impairment with impaired judgment and decision-making capacity develops early in the intoxication process 2
- Mood alterations and increased sociability or aggression may be present 1
Progressive Neurologic Symptoms (Moderate to Severe)
- Impaired coordination and gait instability become evident as blood alcohol levels rise 1, 3
- Speech impairment (slurred speech) is a characteristic finding 1
- Nystagmus (involuntary eye movements) appears with increasing intoxication 1
- Memory impairment and blackouts can occur, with patients unable to recall events during intoxication 1
Gastrointestinal Manifestations
- Nausea and vomiting are common symptoms that can occur at any level of intoxication 1, 4
- These symptoms reflect both direct gastric irritation and central nervous system effects 3
Severe Intoxication (Life-Threatening)
- Altered mental status progressing from confusion to stupor and ultimately coma 1, 4
- Respiratory depression represents the most dangerous complication and can lead to death 1, 4
- Cardiovascular effects including hypotension may develop in severe cases 4
- Central nervous system depression with decreased level of consciousness and loss of protective airway reflexes 1, 3
Autonomic Symptoms
- Diaphoresis (sweating) may be present 5
- Hypothermia can occur, particularly in severe intoxication with environmental exposure 3
Critical Clinical Considerations
The extent of acute intoxication depends on multiple factors beyond blood alcohol concentration alone, including tolerance from chronic use, concurrent medications or substances, and individual metabolic differences 3. Patients with chronic alcohol use may appear less impaired at blood alcohol levels that would severely affect alcohol-naive individuals 2.
Cognitive function should be assessed individually rather than relying solely on blood alcohol concentration to determine capacity for psychiatric evaluation or medical decision-making 2. There is no evidence-based blood alcohol threshold at which cognitive abilities can be reliably predicted 2.
Common Diagnostic Pitfalls
- Alcohol intoxication can mimic or mask other serious conditions including head trauma, hypoglycemia, infection, and other toxic ingestions 2, 3
- Patients presenting with intoxication require thorough evaluation for concurrent medical problems, particularly if they have chronic alcohol dependence 3
- The diagnosis is often complicated by patient denial or minimization of alcohol consumption 1
- Assessment of timing of last alcohol intake is critical to anticipate and prevent alcohol withdrawal syndrome 1