Clinical exam · History taking and the interview
Medicines, allergies and habits: tobacco, alcohol and other substances !
- History
Knowing a patient's medicines, allergies and use of tobacco, alcohol or other substances prevents errors and explains many symptoms.
Updated 2026-11-01
What it is
This part of the past history gathers the medicines the patient uses, their allergies and their substance use. It is key to safety: a poorly recorded allergy or a missed interaction causes avoidable harm. Tobacco and alcohol are major causes of illness and death worldwide, so every patient is asked about them, without judgment and with concrete questions.
What it must include
- A complete list of medicines with how they are taken and adherence.
- Allergies: substance, type of reaction, date and severity; or 'no known allergies'.
- Tobacco: type, amount, years, pack-years; exposure to wood smoke or second-hand smoke.
- Alcohol: frequency, amount, binge episodes and the screening result.
- Other substances: type, route, frequency and last use.
How to ask
- 'What medicines do you take, including those bought without a prescription, herbal products and vitamins?'
- 'How and how often do you take them? Do you ever forget?'
- 'Are you allergic to any medicine, food or latex? What exactly happened?'
- 'Do you smoke or have you smoked? How many cigarettes a day and for how many years? Do you vape?'
- 'Do you drink alcohol? How often, and how much on a typical day?'
- CAGE: 'Have you felt you should cut down? Have people annoyed you by criticising your drinking?'
- CAGE: 'Have you felt guilty about drinking? Have you had a drink first thing in the morning to steady your nerves or a hangover?'
- 'Have you used any other substance, such as cannabis or cocaine? Ever injected?'
Test yourself
Think of the answer, then tap the question to see it.
How are pack-years calculated?
Multiply the number of cigarettes per day by the years of smoking and divide by 20; the result is expressed in pack-years.
What do the four CAGE questions assess?
Whether the person has felt they should cut down, been annoyed by criticism, felt guilty and needed a morning drink; two or more positive answers suggest an alcohol problem.
Why is 'allergic to penicillin' not enough?
Because the reaction must be recorded: hives or anaphylaxis are true allergies, whereas nausea is usually a side effect.
Which products are often forgotten when asking about medicines?
Over-the-counter products, herbal remedies, supplements, contraceptives and medicines the patient uses only now and then.
Related
- Past medical, surgical, family and social history
- The clinical history: its parts and their order
- Comprehensive geriatric assessment: function, cognition, falls
Related conditions
- Alcohol use disorder
- Anaphylaxis
- Opioid use disorder, overdose and withdrawal
- Chronic obstructive pulmonary disease (COPD)
- Lung cancer
Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.
Sources: Drug allergies: MedlinePlus Medical Encyclopedia (U.S. National Library of Medicine, 2025); Tobacco and nicotine (World Health Organization, 2025); Alcohol (World Health Organization, 2024); The Alcohol Drinking History - Clinical Methods - NCBI Bookshelf (Butterworths (NCBI Bookshelf), 1990).
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Representative model, for educational purposes only.