A medical history is a report that includes information gained from a patient's medically relevant recollections (e.g., symptoms, concerns, past diseases) and questioning regarding their concerns. While a physician should generally take their time to take a thorough history, situations such as medical emergencies may only provide enough time for a short history to avoid delaying potentially vital interventions. Because it takes some practice to distinguish between important and irrelevant information, it is best to follow a set protocol in the beginning. Medical history provides the basis on which diagnosis and treatment are developed. An uninterrupted setting in a quiet room with only the examiner and the patient present ensures that patients can openly discuss their concerns and reinforces the patient-physician relationship. This article provides an overview of what a general medical history should cover. Depending on the patient's concerns, additional and/or more targeted questions may be appropriate. See the articles “Pediatrics: history and physical examination” and “OB/GYN: history and physical examination” for further details about those patient groups.
Basics of history taking
- Description: The patient's medical history is typically the first contact between the physician and patient.
- Establish a good physician-patient relationship
- Precise documentation of symptoms
- Develop a differential diagnosis
- Uninterrupted environment: a quiet room without other patients, if possible
- Only the patient should be present, unless:
- The patient requests the presence of a trusted individual
- In children, the presence of a parent or guardian is important or mandatory and, in most cases, simplifies taking the patient's history.
- If there is a language barrier between the patient and yourself, you are required to organize an interpreter, either via phone, video, or in person.
- Key elements
Types of health history
- Problem-focused: only includes CC and brief HPI; usually taken in emergency setting.
- Expanded problem-focused: includes CC, brief HPI, and pertinent ROS; usually when patient is already under the ongoing care of a provider or presents with a specific CC.
- Comprehensive: covers all key elements (mentioned above); usually performed on new, nonemergency patients.
A thorough medical history is the basis for diagnosis. At the beginning of your clerkship, it is recommendable that you take a history according to a standardized scheme that covers the key elements. The more experience you acquire in taking a patient's medical history, the more you will be able to readily determine what areas to focus on.
It may be helpful to begin the interview with a few general questions about the patient's life, e.g., profession and familial status, as they may serve as an icebreaker.
- Description: the main reason for the patient's visit 
- Goal: Record the chief concern clearly in the patient's own words, e.g.,“knee hurts,” “upset stomach,” “runny nose.”
- When taking the patient's medical history, the first question should be as open as possible in order to enable the patient to freely describe their concerns. Examples include:
- ”How may I help you?”
- ”What brings you here today?”
- Description: a detailed description of the chief concern and progression of the symptoms
- Onset of symptoms (context and location)
- Quality and intensity of symptoms (scale from 1 to 10, with 1 indicating a low amount and 10 the maximal intensity of symptoms)
- Course (sudden, gradual, constant, or on and off)
- Duration of symptoms
- Associated symptoms
- Factors that improve or exacerbate symptoms
- Triggers or the patient's own explanation of the cause of the symptoms
Types of HPI
- Brief HPI: includes 1–3 elements
- Extended HPI: includes ≥ 4 elements
- Intensity (on a scale of 1 to 10)
- Quality (e.g., sharp, aching, burning, pressure-like pain)
- Aggravating factors
- Alleviating factors
- Associated symptoms
Another useful mnemonic to help remember the key points of HPI is COLD REARS SIT.
- Character of chief complaint (severity, type)
- Duration (+ progression)
- Exacerbating factors or triggers
- Alleviating factors
- Related symptoms
- Sick contacts/Similar symptoms previously
- Insight into cause
- Treatments tried/Travel
- Description: a patient's health status prior to the current visit 
- Identifying important clues and contributing factors regarding the current concern.
- Developing a holistic approach to patient care
- Childhood illnesses
- Major adult illnesses
- Past surgical history, including type, date, and location of past surgical procedures
- Prescription drugs
- Over-the-counter drugs
- Herbal remedies
- Doses and frequencies
- Drugs or environmental factors
- Reaction to each allergen
- Food intolerance
- Prior injuries (e.g., motor vehicle accidents, falls)
- Prior hospitalizations and/or transfusions
- Screening exams (e.g., Pap smear, mammogram, colonoscopy)
- Psychiatric illnesses, including any psychological intervention or hospitalization
To remember the key points of past medical history, recall the mnemonic PAM HITS FOSS.
PAM HITS FOSS
- Past medical history
- Allergies including drug names and associated adverse effects
- Medications, including over-the-counter as well as prescription medications, and compliance
- Hospitalization in the past
- Ill contacts
- Family history
- OB/GYN procedures
- Sexual history
- Social history
- Description: a history of disease in first- and second-degree blood-relatives that reaches back at least two generations
- Detecting hereditary patterns of disease
- Identifying contagious diseases
- Analyzing risks and providing preventive measurements
Key elements 
- Age and health status of first-degree blood relatives
- List of major medical conditions of first-degree blood relatives
- Age of onset
- Genetic defects (e.g., cystic fibrosis, beta thalassemia, hemophilia, Huntington disease, glycogen storage diseases)
- Living status of first-degree blood relatives
- Description: a part of a medical history that addresses social aspects (e.g., occupation, socioeconomic status, drug use) of the patient's life that might be pertinent to the current medical condition 
- Getting to know a new patient as a person
- Acquiring enough information to support accurate decision-making and choosing an appropriate treatment option
- Promoting healthy behaviors and lifestyle
- Personal data (e.g., place of birth, history of childhood and adolescence, level of education, and marital status)
- Occupation and current job
- Socioeconomic status and living situation
- Safety and health counseling on lifestyle hazards
- Social support
- Exercise and sports
- Interests and hobbies including recent travel and recreational activities
- Performance of ADLs and IADLs
- Sexual history
- Drug and alcohol use
- Religion and spiritual beliefs 
- Description: a list of questions, arranged by organ systems, to help establish the causes of signs and symptoms
- Comprehensive: covers all organ systems; usually done during an initial general health maintenance visit when the patient has no specific concerns.
- Focused: covers only the specific organ systems most likely to be connected to the chief concern
You do not have to ask every question; tailor the questionnaire to the patient and their chief concern (e.g., sexual history may not be relevant if the reason for the visit is an ankle fracture follow-up). Use your best judgment about what to ask and what to leave out, keeping in mind you generally have no more than 10–15 minutes per interview.
ROS questionnaire 
- General state of health including energy, strength, exercise tolerance?
- Fever or chills?
- Night sweats?
- Changes in weight?
- Changes in appetite?
- Trouble sleeping?
- Glasses or contacts?
- Change in visual acuity?
- Blurry or double vision?
- Ability to see at night?
- Ocular discharge/excessive tearing?
- Flashing lights, floaters, or blind spots?
- Yellowish discoloration of sclera?
- Last eye exam?
Head and neck
Ear, nose, mouth, and throat (ENT)
- Mouth and throat
- Chest pain or tightness (on exertion or at rest)?
- Palpitations (on exertion or at rest)?
- Dyspnea (shortness of breath on exertion or at rest)?
- Peripheral edema (leg or ankle swelling)?
- Paroxysmal nocturnal dyspnea (sudden awakening from sleep with shortness of breath)?
- Orthopnea (shortness of breath when lying down)?
- Syncope (dizziness, fainting spells)?
- Cough (dry or wet, productive)?
- color, amount, and occurrence (e.g., green/yellow, bloody, particularly after waking up)?
- Asthma or wheezing?
- Dyspnea (shortness of breath)?
- Painful breathing?
- Dysphagia (swallowing difficulties)?
- Nausea or vomiting?
- Hematemesis (bloody vomiting)?
- Change in appetite?
- Abdominal pain?
- Abdominal distention/bloating?
- Early satiety?
- Jaundice (yellow eyes or skin)?
- Rectal pain?
- Changes in bowel movement
- Change in stool appearance
- Clay-colored stools?
- Acholic stools (pale/white)?
- Tar-colored (black) stools?
- Bloody stools?
- Frequent or urgent urination?
- Dysuria (burning or painful urination)?
- Nocturia (excessive urination at night)?
- Dribbling of urine?
- Change in urinary strength?
- Hematuria (blood in urine)?
- Other changes in urine appearance (e.g., foamy, brown)?
- Female patients
- Male patients
- Muscle or joint pain?
- Joint swelling?
- Joint redness?
- Joint stiffness?
- Bony deformity?
- Muscle weakness?
- Muscle atrophy?
- Back pain?
- Pruritus (itching)?
- Changes in pigmentation and skin color (e.g., yellowish discoloration of skin)?
- Hair loss/gain?
- Changes in nails (e,g, clubbing, ridges)?
- Change in memory?
- Change in speech?
- Recurring or frequent headaches?
- Convulsions or seizures?
- Sensory changes (e.g., paresthesia/numbness, tingling)?
- Paralysis (loss of strength)?
See neurological examination for more information.
- Mood swings?
- Problems with concentration?
- Unusual perception or hallucinations?
- Insomnia (difficulty sleeping)?
- Psychiatric disorder?
Seefor more information.
- Heat or cold intolerance?
- Excessive sweating?
- Weight gain or loss?
- Change in appetite?
- Polyuria (frequent urination)?
- Menstrual irregularities?
- Thyroid enlargement or tenderness?
- Increased or decreased thirst?
- Change in size of head or hands?
- Hormone therapy?
- Recurrent and easy bruising?
- Recurrent bleeds on minor trauma?
- Previous blood transfusion and reactions?
- Lymph node enlargement or tenderness?
- Claudication (calf cramping) with walking or at rest?
At the end of history taking, ask the patient for their primary care physician (PCP). Potential previous findings can be obtained from their PCP. Furthermore, interim or discharge reports are sent to the PCP.