Overview of alcohol use

Unhealthy alcohol use is any level of alcohol use associated with potential or actual harm and affects approximately 1 in 4 Americans. Unhealthy alcohol use can result in acute alcohol intoxication, alcohol use disorder (AUD), and alcohol withdrawal, as well as complications of alcohol use that include an increased risk of chronic liver disease, cancers, heart disease, injury, and premature death. All adults should be screened at least annually for unhealthy alcohol use; those with a positive screening should be evaluated for complications of alcohol use and offered assistance to reduce alcohol intake. The SBIRT approach (screening, brief intervention, and referral to treatment) is used to guide management. Patients with evidence of AUD or complicating comorbidities should be referred for specialist treatment. All other patients should be offered a brief intervention for alcohol cessation. Unhealthy alcohol use is often a chronic condition that requires long-term management.

Common complications of alcohol use are covered in “Alcohol intoxication,” “Alcohol use disorder,” “Alcohol withdrawal,” and “Alcoholic liver disease.”

• Approx. 1 in 4 adults have unhealthy alcohol use. ^[1][2]
• Approx. 90,000 of alcohol-related deaths occur every year in adults aged 20–64 years (1 in 8 total deaths). ^[3]
• Third most common cause of preventable deaths ^[1]

Epidemiological data refers to the US, unless otherwise specified.

Multiple terms are used by different medical societies to classify levels of alcohol consumption; even when the same terms are used, definitions often vary. ^[1]

Quantifying alcohol consumption

The following are based on a US standard drink , which is an alcoholic drink containing 14 g (0.6 fl oz) of pure alcohol. ^[4][5][6]

• Light to moderate alcohol use: a pattern of drinking in a single day that has a low risk of alcohol-related complications ^[5][7]
  • ♀: ≤ 1 standard drink a day
  • ♂: ≤ 2 standard drinks a day
• Heavy alcohol use: consumption of an excessive number of standard drinks ^[1][5]
  • ♀: ≥ 4 standard drinks per day or ≥ 8 standard drinks per week
  • ♂: ≥ 5 standard drinks per day or ≥ 15 standard drinks per week
• Binge drinking: consumption within a 2-hour period of ≥ 4 standard drinks for women and ≥ 5 standard drinks for men ^[1][7]

Even light alcohol use increases the risk of certain cancers; patients who are already abstinent should be encouraged to remain so. ^[8]

Definitions of unhealthy alcohol use ^[1]

Unhealthy alcohol use is a level of alcohol consumption that has caused or has the potential to cause harm.

• Excessive alcohol use: heavy drinking, binge drinking, or any drinking in individuals for whom abstinence is recommended ^[1]
• Hazardous alcohol use: The amount of alcohol consumed may cause alcohol-related complications. ^[5][9]
• Harmful alcohol use: The amount of alcohol consumed has already caused alcohol-related complications. ^[5][9]
• Alcohol use disorder: a pattern of alcohol use that causes significant physical and psychosocial impairment or distress ^[10][11]

Recommended limits for alcohol intake and definitions for alcohol consumption are based on cisgender individuals. There are currently no specific guidelines for transgender individuals and it is unclear what effects gender-affirming hormone therapy may have on alcohol metabolism. ^[12]

• Routinely screen all adults for early identification and management of unhealthy alcohol use.
• Diagnostic studies to confirm alcohol use are not usually required.
• Assess all patients with a positive screening for complications of alcohol use.

Screening is necessary in all adults because unhealthy alcohol use is often overlooked; in two-thirds of cases of unhealthy alcohol use detected on screening, doctors had previously assumed light to moderate alcohol use. ^[13]

Indications ^[1]

• Adults aged ≥ 18 years: Consider at annual visits. ^[11][14][15]
• Individuals aged < 18 years: See “Adolescent health.”
• Pregnant individuals: during the first trimester (see “Prenatal care”)
• More frequent screening may be indicated based on clinical judgment (e.g., patients with psychosocial issues) or chronic conditions (medical or psychiatric) that may be exacerbated by alcohol use. ^[11]

Screening for unhealthy alcohol use is underutilized: Only 1 in 6 adults in the US have ever been asked about their alcohol consumption by a health care professional. ^[16]

Approach ^[13][14][15]

• Alcohol use of any amount is considered positive screening for individuals who: ^[17]
  • Are pregnant or may become pregnant
  • Use medications that can lead to adverse effects if taken with alcohol
  • Have medical or psychiatric conditions that are contraindications for alcohol use
• For all other patients: Use initial screening tests to identify unhealthy alcohol use.
• If initial screening tests are positive: Perform the AUDIT questionnaire to screen for AUD.

Initial screening tests

Preferred screening tests ^[1]

The following tests can be used to assess for all forms of unhealthy alcohol use.

• Single alcohol screening question (SASQ):
  • “Within the past 12 months, how many times have you had ≥ 5 drinks (for men ≤ 65 years) or ≥ 4 drinks (for women; men > 65 years) in a day?” ^[1]
  • A positive screen is on ≥ 1 occasion.
• AUDIT-C test : 3-item questionnaire ^[1][18]

Alternative screening tests

The following tests are sometimes used as an initial screen for AUD, but cannot help to detect other forms of unhealthy alcohol use. ^[1]

CAGE questionnaire ^[1]

• 4-item questionnaire
  • Cut down drinking: Have you ever felt you should cut down on your drinking?
  • Annoyed: Have people annoyed you by criticizing your drinking?
  • Guilty: Have you ever felt guilty about drinking?
  • Eye-opener: Have you ever felt you needed a drink first thing in the morning (eye-opener) to steady your nerves or to overcome a hangover?
• ≥ 2 affirmative answers: Screen for alcohol use disorder (e.g., with AUDIT). ^[13]

Abbreviated forms of the Michigan alcohol screening test (MAST)

• Versions: brief MAST, short MAST (SMAST), and SMAST-geriatric ^[20][21]
• Does not quantify alcohol use and can therefore miss heavy drinking ^[22]

AUDIT questionnaire ^[1][17][18]

• Typically performed if SASQ or AUDIT-C test are positive
• 10-item questionnaire; scored from 0–40 ^[23][24]
  • Scores of ≥ 8: associated with hazardous and harmful alcohol use
  • Score ≥ 15 suggests AUD; proceed to diagnostics for AUD.

Indications ^[13]

• Ongoing monitoring of unhealthy alcohol use
• Confirmation of abstinence
• To help diagnose AUD
• Patients who are unable to self-report alcohol use (e.g., individuals with cognitive impairment)

Confirmation of recent alcohol use ^[11][13][25]

• Blood alcohol level
  • Measured with a rapid test or laboratory study
  • Testing window: ≤ 12 hours since the last alcoholic drink ^[25]
• Ethanol metabolite tests ^[26]
  • Fatty acid ethyl esters
    • Sample collection: multiple tissue types, usually blood or hair
    • Testing window: typically ≤ 24 hours since the last alcoholic drink, but alcohol may be present for up to 8 days ^[25][27]
  • Ethyl glucuronide or ethyl sulfate ^[25]
    • Sample collection: typically urine
    • Testing window: ≤ 5 days since the last alcoholic drink
    • False positives are possible with renal impairment, UTIs, or exposure to low levels of alcohol in foods or products. ^[27]

Confirmation of regular heavy alcohol use ^[13][25]

• Phosphatidylethanol (PEth): a collection of phospholipids that are formed following exposure to alcohol ^[25]
  • The half-life of PEth correlates to the amount and frequency of alcohol intake.
  • Can be detected for up to 28 days since the last drink in individuals with regular heavy alcohol use
  • Cannot detect an isolated episode of alcohol use, only regular use or frequent binge drinking
  • Accuracy is reduced if patients have received a blood transfusion.
• Hair ethyl glucuronide: detects alcohol use in the previous 3 months ^[25]
• Carbohydrate-deficient transferrin: formed when alcohol inhibits transferrin glycosylation ^[25]
  • Can detect regular heavy alcohol use in the previous 2–3 weeks
  • Affected by chronic liver disease, BMI, gender, and iron disorders
• Markers of end-organ dysfunction ^[25]
  • Can help in combination with other tests but lack sensitivity and specificity
  • Examples include abnormal liver chemistries (e.g., elevated GGT) and elevated MCV.

Alcohol use can affect almost all systems of the body; see “Complications of alcohol use.”

Clinical evaluation ^[11][13]

History

Perform a detailed review of systems and obtain collateral history (e.g., from family members and caregivers) when appropriate.

• Psychosocial history ^[27]
  • Current stressors (e.g., family, work)
  • Mood or other psychiatric symptoms (e.g., anxiety, depression) ^[28]
  • Suicidality
  • Aggressive behaviors
• Current and past substance use
  • Tobacco smoking
  • Medication or substance misuse (e.g., opioid use disorder) ^[28]
• Physical symptoms
  • General (e.g., abdominal pain, nausea, diarrhea, headaches) ^[28]
  • Sleep disturbance ^[28]
  • Sexual dysfunction
  • Menstrual cycle abnormalities ^[26]

Consider reviewing the state's prescription drug monitoring program to evaluate for unreported use of medications. ^[11]

Physical examination

• Perform a comprehensive physical examination to assess for alcohol-related complications.
• If abnormalities are identified, order the appropriate studies.

Diagnostic studies for alcohol-related complications

Based on clinical suspicion, order the appropriate studies for alcohol-related complications. ^[28]

Laboratory studies

The following findings are more common in patients with regular heavy alcohol use.

• CBC ^[11][26]
  • Macrocytic anemia (↓ Hb, ↑ MCV)
  • ↓ Platelets ^[26]
  • Iron deficient anemia (↓ iron, ↑ TIBC, ↓ ferritin)
  • Anemia of chronic disease (↓ iron, ↓ TIBC, ↑ ferritin)
• Liver chemistries
  • ↑ GGT
  • ↑ ALT and ↑ AST; (AST > ALT) ^[29]
  • See also “Diagnostics for alcoholic liver disease.”
• BMP and electrolytes
  • ↓ Creatinine ^[13]
  • ↓ Or ↑ glucose ^[26]
  • ↑ Lipase, ↑ amylase ^[26][28]
  • ↓ Sodium, ↓ potassium, ↓ magnesium, ↓ phosphate, ↓ calcium ^[26][28]
• Vitamin levels
  • B vitamins: ↓ vitamin B₁ (thiamine), ↓ vitamin B₆ (pyridoxine), ↓ vitamin B₁₂ (cobalamin) ^[11][26]
  • ↓ Folic acid
  • ↓ Vitamin D
  • ↓ Vitamin K
• Coagulation panel: prolonged PT/INR ^[26][30]
• Lipid levels: ↑ triglycerides ^[26]

Additional testing

Additional testing is performed based on clinical features.

• Cardiac symptoms : ECG and echocardiography ^[26][28]
• Abnormal neurological findings: neuroimaging ^[28]
• Symptoms of alcoholic hepatitis, symptoms of cirrhosis, or diagnosis of AUD: liver ultrasound ^[28][31]

Heavy alcohol use may have an impact on recommendations or frequency of screening programs, e.g., screening for osteoporosis. ^[28][32]

The SBIRT approach is used to guide management.

Approach

• Manage any acute alcohol-related complications before further management steps; see:
  • “Management of alcohol intoxication”
  • “Management of alcohol withdrawal”
  • “Management of Wernicke encephalopathy”
• Further management depends on drinking behavior and the desire to change.
  • Patients who want to change alcohol use
    • Evidence of AUD or complicating comorbidities, e.g., mental health conditions: Refer for treatment (see “Management of AUD”).
    • Unhealthy alcohol use but no evidence of AUD: Offer a brief intervention. ^[28]
  • Patient who do not want to change alcohol use
    • Advise patients that they can return at any point to discuss alcohol use.
    • Regularly review patients for complications of alcohol use.
• Discuss harm-reduction strategies with all patients.
• Identify and treat any medical complications of alcohol use; referral to a specialist may be required.
• Arrange follow-up and advise patients they can return at any point prior to that to discuss alcohol use.

For patients who are abstinent or drink within the recommended guidelines, offer positive reinforcement and reiterate the guidelines for healthy alcohol use and when complete abstinence is recommended (e.g., during pregnancy). ^[17]

Brief intervention for alcohol use ^[14][28]

• Discussion of risk based on patient's screening results.
• Provide brief counseling (e.g., using motivational interviewing or the 5 As model of behavior change).
• Educate on the standard drink and low risk alcohol use. ^[5]
• Use shared decision-making to agree goals, e.g.: ^[11]
  • Abstinence
  • Decrease alcohol consumption to recommended amount (e.g., light to moderate alcohol use) ^[7]
  • No alcohol use in situations that may cause harm to themselves or others (e.g., drinking before driving)
  • Fewer drinking days ^[17]

Advise full abstinence for those who are planning to conceive, taking medications that can cause harmful drug interactions (e.g., metronidazole), or have chronic comorbidities that may worsen alcohol use (e.g., alcoholic liver disease).

Follow-up for unhealthy alcohol use ^[14][28]

• Follow-up should be tailored to the patient's physical and mental health needs.
• Consider follow-up within 24 hours–1 week for patients starting treatment for AUD or at risk for alcohol withdrawal. ^[14][26][28]
• Schedule a follow-up visit in 1–3 months for patients who have undergone a brief intervention. ^[17]
• At the follow-up visit:
  • Discuss progress toward goals. ^[14]
  • Modify treatment plans as needed. ^[14]
  • Consider monitoring CDT or GGT levels for positive reinforcement. ^[28]
  • If needed, repeat monitoring for complications of alcohol use.
• For patients who have relapsed, shorten intervals between repeat follow-ups. ^[14]
• Patients usually require long-term monitoring and treatment because unhealthy alcohol use is often a chronic condition.

Relapse is extremely common among patients with unhealthy alcohol use; discuss triggers for relapse and encourage patients to view relapses as learning opportunities rather than failures. ^[14]

Cardiac complications

• Alcohol-induced atrial arrhythmia
• Ischemic heart disease ^[28]
• Hypertension ^[28]
• Alcohol-induced cardiomyopathy ^[33][34]
  • Definition: acquired dilated cardiomyopathy following regular heavy alcohol use
  • Clinical features: symptoms of heart failure
  • Diagnosis
    • History of regular heavy alcohol use
    • Echocardiography
      • Dilation and impaired contractility of one or both ventricles
      • Normal or reduced thickness of ventricular walls
      • Systolic and diastolic dysfunction
    • Exclusion of other possible causes of dilated cardiomyopathy (e.g., coronary angiography to rule out coronary artery disease)
  • Management
    • Total abstinence from alcohol
    • Treatment of heart failure
    • Thiamine and folate supplementation
  • Prognosis: Ventricular function typically improves and may normalize with abstinence.

Gastroenterological complications

• Erosive gastritis
• Pancreatitis
• Alcoholic liver disease (e.g., steatosis, hepatitis, fibrosis) ^[35]
• Cirrhosis

Neuropsychiatric complications

• Alcohol-related cerebellar degeneration
  • Definition: degeneration of Purkinje cells in the cerebellar vermis due to regular heavy alcohol use
  • Clinical features
    • Gait ataxia
    • Truncal ataxia
    • Gaze-evoked nystagmus
  • Diagnostics: CT or MRI shows atrophy of the cerebellar vermis.
• Marchiafava–Bignami disease
  • Definition: degeneration and necrosis of the corpus callosum, almost exclusively as a result of malnutrition due to regular alcohol use
  • Clinical features
    • Behavioral changes
    • Cognitive impairment and dementia
    • Epileptic seizures
• Other disorders
  • Stroke (hemorrhagic and ischemic) ^[28]
  • Meningitis
  • Mood disturbances: anxiety, depression, irritability, aggression ^[36]
  • Alcoholic hallucinations ^[26][27]
  • Insomnia ^[28]
  • Polyneuropathy ^[28]
  • Central pontine myelinolysis

Multisystem complications

• Cytochrome P450 induction
• Increased risk of malignancy, e.g.: ^[28]
  • Liver cancer
  • Breast cancer
  • Colorectal cancer
  • Head and neck cancers
  • Esophageal cancer
• Vitamin deficiency
  • Vitamin B₁ deficiency (thiamine deficiency): Wernicke-Korsakoff syndrome
  • Vitamin B₆ deficiency: peripheral neuropathy
  • Vitamin B₉ deficiency (folate deficiency): megaloblastic anemia
  • Vitamin B₁₂ deficiency: subacute combined degeneration of spinal cord; (funicular myelosis), megaloblastic anemia
• Alcohol-induced coagulopathy
• Electrolyte abnormalities (see “Evaluation for alcohol-related complications”) ^[28]
• Hematological disorders including anemia (see “Evaluation for alcohol-related complications”) ^[28]
• Zieve syndrome ^[37]

Reproductive complications

• Fetal alcohol syndrome ^[28]
• Preterm birth ^[28]
• Testicular atrophy and gynecomastia ^[26][38]

Musculoskeletal complications ^[39][40]

• Acute alcohol-induced myopathy
  • Definition: acute muscle pain, weakness, and swelling following the consumption of large quantities of alcohol in a short period of time
  • Clinical features
    • Most commonly focal and asymmetric pain of the proximal muscles (mainly the pelvic and shoulder girdles)
    • Can lead to rhabdomyolysis and, subsequently, acute kidney injury (pigment nephropathy)
  • Treatment ^[40]
    • Total abstinence from alcohol: symptoms usually resolve within days to weeks.
    • Optimization of nutrition
• Chronic alcohol-induced myopathy
  • Definition: progressive muscle weakness manifesting over weeks to months in individuals with regular excessive alcohol use
  • Clinical features
    • Most commonly weakness of the proximal muscles
    • Occasionally muscle pain, atrophy, twitching, and/or myotonia
  • Treatment ^[40]
    • Total abstinence from alcohol: symptoms usually resolve within 2 to 12 months.
    • Optimization of nutrition
• Gout: As the level of alcohol intake increases, so does the risk of gout. ^[28]
• Osteoporosis: Heavy alcohol use affects bone density and increases the risk of falls. ^[28]
• Osteonecrosis of the femoral head: associated with heavy alcohol use ^[28]

In acute alcohol-induced myopathy, rhabdomyolysis and subsequent myoglobin release can lead to acute kidney injury.