Alcohol beyond withdrawal: the patient "who is just drunk"

Saturday, almost midnight. A fifty-year-old man arrives brought by strangers who found him sitting on the sidewalk, confused, with alcoholic breath and dirty clothes. During the shift handover, someone sums it up: "He's known to the service, he's just drunk, let him sleep in the hallway and tomorrow he'll be gone". The sentence sounds practical. It also carries three diagnoses that can go unnoticed during the night: a head trauma with bleeding that grows little by little, a hypoglycemia that worsens while he sleeps and a Wernicke encephalopathy that, without treatment, can leave permanent sequelae. This text uses alcohol intoxication as a scenario for clinical reasoning: why the expression "just drunk" is a bias to dismantle, which hypotheses must be checked before accepting alcohol as the explanation and how to reassess the person over time. The scene and the examples in the text are fictional and were written for teaching.

NEXO is a daily medical diagnosis game: one clinical case a day, up to six progressive clues, and ICD-10 proximity feedback across five levels.

The text avoids being a care protocol or a dosing guide. The guidelines and protocols of each service guide the conduct. Here the focus is the way of thinking in the face of an explanation that seems obvious. If you play the case of the day in NEXO, you know the move: a strong clue can push the reasoning toward an entire chapter, and the proximity feedback shows how far you moved away from the answer.

Key points

• Alcoholic breath confirms that there was consumption, and leaves open what is causing the altered level of consciousness.
• Head trauma, hypoglycemia and Wernicke encephalopathy are hypotheses that can coexist with intoxication and that must be checked.
• The classic triad of Wernicke appears complete in a minority of cases, and broader operational criteria help avoid missing the diagnosis.
• Reassessing the person over time is part of the diagnosis: whoever is "just drunk" improves, and whoever worsens calls for another explanation.
• Stigmatizing language and labels such as "known to the service" increase the risk of premature closure.

Why "just drunk" is a dangerous diagnosis

The phrase "just drunk" works as a diagnosis of exclusion done backwards: instead of excluding the other causes and arriving at alcohol, it starts with alcohol and dismisses the search for the others. Pat Croskerry described this move as premature closure, one of the most frequent cognitive errors in emergency medicine (Croskerry, 2003). In the study by Graber, Franklin and Gordon on diagnostic errors in internal medicine, premature closure was the most common cognitive error among the analyzed cases (Graber, Franklin and Gordon, 2005).

Alcohol is an especially strong anchor because it explains many things at the same time. Confusion, slurred speech, unsteady gait, vomiting, drowsiness and aggression can be effects of intoxication. The problem is that these same signs appear in head trauma, hypoglycemia, Wernicke encephalopathy, central nervous system infection, intoxication by other substances, seizures and stroke. When alcohol explains everything, it also hides everything.

The World Health Organization reminds us that alcohol use is linked to injuries, to diseases of several organs and to a large number of deaths worldwide (WHO, alcohol fact sheet). For clinical reasoning, this means that the intoxicated person has increased pre-test probability for several serious conditions, and not only for the intoxication itself. The post on pre-test probability helps to think about how a clue shifts the weight of the hypotheses.

There is also a context effect. Full shifts, late nights and people who arrive without a companion create pressure to resolve things quickly. Under these conditions, fast thinking takes over and the most available explanation wins. The way out is to have a few fixed checkpoints that happen for every person with altered consciousness, with or without alcohol: blood glucose, head examination, neurological examination, serial vital signs and a question about food intake and falls. These checkpoints work as a safety net for reasoning, because they do not depend on first impressions.

The "known to the service" label

People who frequently return to the emergency department in a state of intoxication get nicknames, quick notes and less assessment time. The label travels from one shift to the next. A systematic review showed that negative attitudes of health professionals toward people with substance use disorders are common and are associated with worse quality of care (van Boekel and colleagues, 2013). Each visit is a new episode, with its own hypotheses, even if the person is already known.

When emotion enters the assessment

Treating someone intoxicated, aggressive or dirty in the middle of a busy shift provokes irritation. This emotion influences reasoning, a phenomenon described in the post about affective bias. Recognizing the irritation is the first step to keep it from deciding for us.

The three hypotheses that cannot be missed

Three hypotheses deserve special attention because they are common, serious and treatable, and because they hide well behind intoxication. This group is a reasoning tool, not a complete list of the differential.

Head trauma

Intoxicated people fall, fight and get hurt, often without remembering what happened. The neurological examination becomes hard to interpret, because intoxication also alters consciousness, speech and gait. For this reason, the NICE guideline on head trauma advises attributing reduced level of consciousness to intoxication only after excluding a significant traumatic brain injury (NICE NG232). A hematoma behind the ear, a subtle pupillary asymmetry or drowsiness that takes a while to pass change the weight of the hypotheses. The decision about imaging follows the service's criteria, and serial reassessment helps reveal what the first examination did not show.

Hypoglycemia

Alcohol can cause hypoglycemia, especially in people with low food intake, and hypoglycemia can look like intoxication: confusion, sweating, altered behavior and drowsiness. Capillary blood glucose is quick, cheap and changes management on the spot. It should be part of the initial assessment of anyone with altered level of consciousness, including those with alcoholic breath.

Wernicke encephalopathy

Wernicke encephalopathy is caused by thiamine deficiency and appears frequently in people with heavy alcohol use and inadequate food intake. The classic triad includes confusion, eye changes and ataxia, but an autopsy study of people diagnosed with Wernicke-Korsakoff complex showed that most did not have the complete triad recorded during life and that many cases were identified only after death (Harper, Giles and Finlay-Jones, 1986). Because intoxication also causes confusion and ataxia, Wernicke encephalopathy is one of the easiest hypotheses to miss.

Other hypotheses that come along

Beyond the three main hypotheses, the differential for the intoxicated person includes conditions that also hide behind alcohol. Intoxication by other substances, alone or mixed, is common and changes the picture. An unwitnessed seizure can leave the person confused in the postictal period, and withdrawal itself can cause seizures. A stroke can be mistaken for slurred speech and unsteady gait. Infections, such as aspiration pneumonia and meningitis, can begin with confusion and mild fever. In people with liver disease, hepatic encephalopathy enters the differential. On cold nights, hypothermia in those who spent hours on the street also alters consciousness.

The post about differential diagnosis with clues suggests listing the hypotheses before choosing one. With alcohol in the picture, this short list, written right on arrival, helps keep reasoning open until the data allow a conclusion.

Comorbidities that change how the case is read

Heavy, prolonged alcohol use affects almost every organ, and comorbidities change how intoxication presents. Chronic liver disease alters coagulation, increases the risk of bleeding after trauma and opens the door to hepatic encephalopathy. Pancreatitis can present as abdominal pain and vomiting that look like the effect of alcohol. Electrolyte disturbances, such as changes in sodium, potassium, magnesium and phosphorus, can cause confusion, arrhythmias and weakness. Malnutrition increases the risk of thiamine deficiency and hypoglycemia.

These comorbidities also change the pretest probability of each hypothesis. A person with cirrhosis who arrives confused after a fall is more likely to have intracranial bleeding than a person without liver disease. A person with low food intake and vomiting for days is more likely to have Wernicke. Reasoning needs to take the full history into account, not just the episode of the night. Talking with companions, checking previous records and asking about food intake, falls and other illnesses are simple steps that change the differential.

Fictional example: the night that changes direction

Imagine a woman in her mid-forties brought in by her family after drinking during the day. On arrival, she is drowsy and answers in short sentences. Blood glucose is normal and the head examination shows no visible injuries. Two hours later, she is still drowsy, and the team notices abnormal eye movement and difficulty sitting up. The family says she has been eating little for weeks. With two findings from the operational criteria, the hypothesis of Wernicke gains weight, and treatment follows the service protocol. What changed the case was the reassessment and the conversation with the family, not a sophisticated test.

Wernicke: the diagnosis the triad hides

If the full triad is rare, how should you think about the diagnosis? Caine and colleagues proposed operational criteria for people with chronic alcohol use: the presence of two of four findings, which are dietary deficiency, ocular abnormalities, cerebellar dysfunction and altered mental state or mild memory impairment (Caine and colleagues, 1997). These criteria increase sensitivity compared with the classic triad and help you think about the diagnosis earlier.

The European Federation of Neurological Societies guideline on the diagnosis, treatment and prevention of Wernicke encephalopathy recommends considering the diagnosis on clinical grounds, giving weight to the operational criteria, and treating without waiting for laboratory or imaging confirmation (Galvin and colleagues, 2010). The review by Sechi and Serra in Lancet Neurology also describes scenarios outside alcohol, such as bariatric surgery, persistent vomiting and malnutrition, which broadens the reasoning (Sechi and Serra, 2007).

In the United Kingdom, a report from the Royal College of Physicians provided guidance for managing Wernicke encephalopathy in the emergency department, with emphasis on recognizing risk and treating early (Thomson and colleagues, 2002). The NICE guidelines on physical conditions related to alcohol use and on alcohol use disorders also address the prevention and treatment of thiamine deficiency (NICE CG100; NICE CG115).

The myth that delays glucose

A common teaching says that glucose should never be given before thiamine, because that would precipitate Wernicke encephalopathy. A national retrospective study of veterans treated in emergency departments for alcohol intoxication who received glucose before thiamine found zero diagnoses of Wernicke during follow-up, and the authors concluded that hypoglycemia should be treated without delay (Jasti and colleagues, 2025). For reasoning, the point is priority: hypoglycemia is an immediate threat, and thiamine remains indicated for those at risk. The exact sequence follows the service protocol.

Table: clue, hidden hypothesis and what to check

The table summarizes the clues that often appear in an intoxicated person and the hypotheses that may lie behind them. It is a reasoning map, and management follows the service protocol.

Clue	A guess that may be hiding	What helps to check
Confusion out of proportion to the reported consumption	Hypoglycemia, Wernicke, head trauma, infection	Capillary glucose, neurological exam, history with companions
Hematoma, abrasion or report of a fall	Head trauma with bleeding	Head exam, the service's imaging criteria, serial reassessment
Eye changes or ataxia that persists	Wernicke encephalopathy	Operational criteria, dietary history, empirical treatment per protocol
Sweating, tremor and tachycardia hours later	Alcohol withdrawal or hypoglycemia	Time since last drink, glucose, serial vital signs
Fever or neck stiffness	Central nervous system infection	Complete physical exam, workup per suspicion
Worsening level of consciousness over time	Bleeding, hypoglycemia, another substance	Immediate neurological and metabolic reassessment

Reassess over time: the clue that only shows up later

Alcohol intoxication has a predictable course: the alcohol concentration falls over time and the person tends to improve. That course is itself a diagnostic tool. Someone who is only intoxicated improves. Someone who worsens, or who stays confused when they should be better, calls for another explanation.

That is why serial reassessment is part of the diagnosis. The post on diagnostic pause proposes stopping before closing the case and asking what still needs explaining. With an intoxicated person, this pause needs to happen more than once: on arrival, a few hours later and before discharge.

Questions for each reassessment

• Has the level of consciousness improved as expected for the time elapsed?
• Has the neurological exam changed, for better or for worse?
• Was glucose measured and repeated when necessary?
• Is there any new finding, such as hematoma, fever, asymmetry or eye change?
• Has anyone talked with companions or with whoever brought the person in?

Discharge as part of the reasoning

Discharging a person who was intoxicated is a clinical decision, not an administrative act. It assumes that the person is oriented, that serious hypotheses were considered and that follow-up for the coming days was arranged. If there is a risk to life or intense suffering, advise the person to seek the help they need and make sure they know where to find care. A conversation about alcohol use, held with respect, can be the first door to treatment.

How to talk and document without stigma

The language used in the shift handover and in the medical record influences the decisions of whoever comes next. A randomized study showed that describing the same person as a "substance abuser" instead of a "person with a substance use disorder" increased professionals' tendency to assign blame and to support punitive measures (Kelly and Westerhoff, 2010). Phrases such as "just drunk", "alcoholic" or "complainer" carry judgment and close off the reasoning too early.

A few simple swaps help:

• Replace "drunk" with "person with alcohol intoxication", and record the findings that support this assessment.
• Replace "alcoholic" with "person with alcohol use disorder", when there is a basis for the diagnosis.
• Record the hypotheses that are still open, not just the intoxication.
• Note the time of each reassessment and what changed.
• In the shift handover, say what still needs checking, not only what has already been concluded.

The post on empathy and clinical reasoning in the consultation shows how the way of talking changes the quality of the information. With an intoxicated person, the conversation can be short, but it still needs to be respectful.

The conversation about alcohol before discharge

When the person is oriented, the moment before discharge is an opportunity for conversation. The approach can be short: ask how they see their own drinking, offer information about the risks that appeared that night and ask whether they want help. The NICE guidelines describe ways of assessing and referring people with harmful drinking or dependence. Tone matters more than the script: a conversation without judgment increases the chance that the person comes back when they need to and accepts treatment at another time. If the person refuses, the refusal is recorded with a date, and the offer can be taken up again at a next visit.

This conversation also protects the reasoning of whoever sees the person in the future. A record that describes the drinking, the hypotheses checked and the person's response helps more than a label. It lets the next shift start with information, not with an old label.

How to train with cases and with NEXO

NEXO offers a fictional clinical case per day, with a real clinical presentation and up to six progressive clues. You propose a diagnosis by looking for the code in ICD-10 and receive proximity feedback at five levels, which shows whether your guess landed on the exact code, the same category, the same group, the same chapter or a different chapter. When the first clue is alcohol, the feedback shows whether you stayed stuck in the chapter of mental disorders or considered trauma, the metabolic disturbance and the neurological disease.

Three exercises to train with cases

The post about case-based learning in clinical practice explains why studying with cases fixes decisions better. Three exercises help train reasoning in the face of intoxication:

Take alcohol out of the vignette. Read a case with intoxication and ask what diagnosis you would make if the alcoholic breath were not there.

Write the three hypotheses that cannot be missed. For each case with alcohol, note trauma, hypoglycemia and Wernicke, and the finding that would help rule out each one.

Rewrite the handover. Take a fictional sentence like "he's just drunk, let him sleep" and rewrite it with open hypotheses, the time of the next reassessment and what still needs checking.

These exercises match the idea of calibration from the post about calibrating confidence in diagnosis and the strategies from the post about diagnostic uncertainty.

The limits on using the game are described on the NEXO Economy page. If you research the teaching of clinical reasoning, the page for Researchers explains how to get in touch. Professionals who write or review cases find information under Curator and Creators, and institutions can learn about the proposal on the partnerships page.

Frequently asked questions

Does alcoholic breath confirm that the confusion is due to intoxication?

The breath confirms that alcohol was consumed. The cause of the confusion still needs to be assessed, because head trauma, hypoglycemia, Wernicke and other conditions can coexist with intoxication.

Is the classic triad necessary to think of Wernicke?

The full triad appears in a minority of people with the diagnosis. Operational criteria that require two of four findings help recognize the condition earlier.

Can I give glucose before thiamine?

A recent study with veterans suggests that hypoglycemia should be treated without delay, and thiamine remains indicated for those at risk. The sequence follows the service protocol.

Does every intoxicated person need a head CT?

The decision follows the service criteria and the clinical assessment. The reasoning point is to attribute the reduced level of consciousness to intoxication only after ruling out a significant traumatic brain injury (NICE NG232), and serial reassessment is part of the decision.

Does this text serve as a care protocol?

This text deals with clinical reasoning and biases. Approaches and doses follow your service protocols and the guidelines of medical societies, under supervision.

How does this topic appear in exams?

Exams often test recognition of Wernicke encephalopathy, the priority of blood glucose in altered consciousness and the differential of the intoxicated patient with trauma. Practicing with cases helps connect these points.

Final checklist

• I measured blood glucose on arrival and repeated it when necessary.
• I examined the head and followed the service's imaging criteria.
• I considered Wernicke using operational criteria, not just the triad.
• I reassessed the level of consciousness and the neurological exam over time.
• I recorded the open hypotheses in neutral language.
• I decided on discharge with the person informed and with follow-up arranged.

Want to practice reasoning with progressive clues? Play the case of the day.

References

1. Caine D, Halliday GM, Kril JJ, Harper CG. Operational criteria for the classification of chronic alcoholics: identification of Wernicke's encephalopathy. J Neurol Neurosurg Psychiatry. 1997. [PMID 9010400](https://pubmed.ncbi.nlm.nih.gov/9010400/).
2. Croskerry P. The importance of cognitive errors in diagnosis and strategies to minimize them. Acad Med. 2003. [PMID 12915363](https://pubmed.ncbi.nlm.nih.gov/12915363/).
3. Galvin R, Bråthen G, Ivashynka A, et al. EFNS guidelines for diagnosis, therapy and prevention of Wernicke encephalopathy. Eur J Neurol. 2010. [PMID 20642790](https://pubmed.ncbi.nlm.nih.gov/20642790/).
4. Graber ML, Franklin N, Gordon R. Diagnostic error in internal medicine. Arch Intern Med. 2005. [PMID 16009864](https://pubmed.ncbi.nlm.nih.gov/16009864/).
5. Harper CG, Giles M, Finlay-Jones R. J Neurol Neurosurg Psychiatry. 1986. [PMID 3701343](https://pubmed.ncbi.nlm.nih.gov/3701343/).
6. Jasti J, Sherman K, Gummin D, Farkas A. Prevalence of Wernicke's Encephalopathy When Receiving Dextrose Before Thiamine: A National Study of Veterans. Acad Emerg Med. 2025. [PMID 40873301](https://pubmed.ncbi.nlm.nih.gov/40873301/).
7. Kelly JF, Westerhoff CM. Does it matter how we refer to individuals with substance-related conditions? A randomized study of two commonly used terms. Int J Drug Policy. 2010. [PMID 20005692](https://pubmed.ncbi.nlm.nih.gov/20005692/).
8. National Institute for Health and Care Excellence. Alcohol-use disorders: diagnosis and management of physical complications (CG100). [NICE CG100](https://www.nice.org.uk/guidance/cg100).
9. National Institute for Health and Care Excellence. Alcohol-use disorders: diagnosis, assessment and management of harmful drinking and alcohol dependence (CG115). [NICE CG115](https://www.nice.org.uk/guidance/cg115).
10. National Institute for Health and Care Excellence. Head injury: assessment and early management (NG232). 2023. [NICE NG232](https://www.nice.org.uk/guidance/ng232).
11. Sechi G, Serra A. Wernicke's encephalopathy: new clinical settings and recent advances in diagnosis and management. Lancet Neurol. 2007. [PMID 17434099](https://pubmed.ncbi.nlm.nih.gov/17434099/).
12. Thomson AD, Cook CC, Touquet R, et al. The Royal College of Physicians report on alcohol: guidelines for managing Wernicke's encephalopathy in the accident and Emergency Department. Alcohol Alcohol. 2002. [PMID 12414541](https://pubmed.ncbi.nlm.nih.gov/12414541/).
13. van Boekel LC, Brouwers EP, van Weeghel J, et al. Stigma among health professionals towards patients with substance use disorders and its consequences for healthcare delivery: systematic review. Drug Alcohol Depend. 2013. [PMID 23490450](https://pubmed.ncbi.nlm.nih.gov/23490450/).
14. World Health Organization. Alcohol: fact sheet. [WHO](https://www.who.int/news-room/fact-sheets/detail/alcohol).