What are the parts of a medical history?

A complete history has the chief complaint, the history of present illness, past medical and surgical history, medications and allergies, family history, social history and a review of systems. It ends with a summary back to the patient and a chance for them to add anything.

How long should taking a history take?

A focused history for a single complaint usually takes 10 to 15 minutes; a full admission history can take 30 minutes or more. In an OSCE station you typically have 7 to 10 minutes, so the history of present illness gets most of the time and the background is asked briefly.

What is the difference between the chief complaint and the history of present illness?

The chief complaint is the reason for the visit in the patient's own words, with its duration, such as "chest pain for two hours." The history of present illness is the detailed story of that complaint: when it started, how it has changed, its character, what makes it better or worse, associated symptoms and what the patient has already tried.

How can I practice taking a history?

Practice on real or simulated patients, out loud, against a structure, and get feedback on what you missed. Clerkshift lets you interview simulated patients adapted from published case reports, who answer only what you ask, then grades your history, diagnosis and plan.

Updated November 10, 2026

How to take a medical history: a step-by-step guide

In most cases, the history alone points to the diagnosis. The examination and the tests then confirm or refine what the history suggested. A good history follows a structure, so nothing important is missed, but it is still a conversation: let the patient tell their story, then fill in the gaps.

1. Introduce yourself and set the scene

Introduce yourself by name and role, confirm the patient's name and date of birth, and ask for their consent to talk. Make sure they are comfortable and that you will not be interrupted. A minute spent here makes the rest of the interview easier.

2. The chief complaint

Start with an open question: "What brought you in today?" Then listen without interrupting. Record the complaint in the patient's own words and how long it has been going on, for example "chest pain for two hours."

3. History of present illness

This is the heart of the history. Explore the main symptom in detail, then ask about the symptoms that go with it. For pain, a mnemonic such as OPQRST, OLDCARTS or SOCRATES keeps you thorough:

Onset: when did it start, and was it sudden or gradual?
Provocation and palliation: what makes it worse or better?
Quality: what does it feel like?
Region and radiation: where is it, and does it spread?
Severity: how bad is it, from 0 to 10?
Timing: is it constant or does it come and go? Has it changed?

Then ask the questions that would point toward or away from the conditions on your differential. These pertinent positives and negatives are what turn a list of symptoms into a diagnosis. Ask what the patient thinks is going on and what worries them most.

4. Past medical and surgical history

Ask about long-term conditions, previous hospital admissions, operations and significant illnesses. Prompt for the common ones: diabetes, high blood pressure, heart disease, asthma or COPD, stroke and kidney disease.

For patients who could be pregnant, take an OB/GYN history: the last menstrual period, the chance of pregnancy, and previous pregnancies.

5. Medications and allergies

List every medication with its dose and how often it is taken, including over-the-counter drugs, supplements and anything recently started or stopped. Ask whether the patient actually takes them as prescribed. For each allergy, ask what the reaction was: a rash and anaphylaxis call for very different caution. Distinguish a true allergy from an intolerance or a side effect, such as nausea with an antibiotic.

6. Family history

Ask about conditions in first-degree relatives, especially heart disease or sudden death at a young age, cancers, diabetes and inherited conditions. Note the age at which relatives were affected.

7. Social history

Smoking: what, how much, for how long. Calculate pack-years.
Alcohol: how many standard drinks a week. Screen for harmful use with a tool such as AUDIT-C or CAGE.
Recreational drugs, including how they are taken.
Occupation and exposures, now and in the past.
Home situation: who they live with, stairs, and how they manage day to day.
Travel, sexual history and pets, when relevant to the complaint.

8. Review of systems

Finish with a quick screen of each body system for anything not yet covered: constitutional symptoms such as fever and weight loss, then HEENT (head, eyes, ears, nose and throat), cardiovascular, respiratory, gastrointestinal, genitourinary, musculoskeletal, skin, neurological, endocrine, hematologic and psychiatric. It often turns up a symptom the patient did not think was related.

9. Summarize and check

Summarize what you have heard back to the patient and ask whether you have missed anything. Then say what happens next. When you present the case, open with a one-line summary: age, sex, relevant background and the chief complaint.

Common mistakes

Asking closed questions too early, before the patient has told their story.
Stopping at the first diagnosis that fits, without asking what would rule it out.
Recording drug names without doses, or allergies without the reaction.
Leaving out the social history, which often explains why the patient presented now.
Using jargon the patient does not understand.

Frequently asked questions

What are the parts of a medical history?: A complete history has the chief complaint, the history of present illness, past medical and surgical history, medications and allergies, family history, social history and a review of systems. It ends with a summary back to the patient and a chance for them to add anything.
How long should taking a history take?: A focused history for a single complaint usually takes 10 to 15 minutes; a full admission history can take 30 minutes or more. In an OSCE station you typically have 7 to 10 minutes, so the history of present illness gets most of the time and the background is asked briefly.
What is the difference between the chief complaint and the history of present illness?: The chief complaint is the reason for the visit in the patient's own words, with its duration, such as "chest pain for two hours." The history of present illness is the detailed story of that complaint: when it started, how it has changed, its character, what makes it better or worse, associated symptoms and what the patient has already tried.
How can I practice taking a history?: Practice on real or simulated patients, out loud, against a structure, and get feedback on what you missed. Clerkshift lets you interview simulated patients adapted from published case reports, who answer only what you ask, then grades your history, diagnosis and plan.