History-taking is a problem-based approach to gaining information in the pre-hospital environment, with an emphasis on identifying life-threatening conditions that require immediate intervention.

Communication

Communicating with the patient is very important when obtaining a patient history.

Proper techniques of questioning include using

• open-ended questions (allow the patient to answer beyond "yes" or "no," which often provides more assessment information),
• direct questions, and
• leading questions.

In the best of circumstances, the patient can answer all questions about his or her chief complaint and medical history. This information may be obtained from family, friends, bystanders, public safety personnel, and medical identification jewelry when necessary.

Mechanism of Injury or Nature of Illness

The mechanism of injury refers to the possible forces that have caused an injury. Determining the mechanism of injury may help predict the severity of injuries and the presence of other injuries.

The nature of the illness is the type of illness the patient is experiencing. EMS providers can ask the patient, family members, or bystanders why EMS was called, but should remember to look for clues in the environment as well and be aware of hot or cold environments and the presence of drugs or poisons.

Associated Signs and Symptoms

EMS providers should ask the patient to describe the current problem and events leading up to the illness or injury.

Signs are defined as any medical or trauma assessment findings that can be seen, felt, or heard by the EMS provider and documented objectively. Examples of signs include blood pressure (auscultated or listened-to) or observing an open wound (visual).

Signs, while associated with the history, are part of the physical exam or physical assessment/evaluation.

Symptoms are defined as any medical or trauma condition that is described to the EMS provider by the patient subjectively. Examples of symptoms include a patient verbally advising EMS personnel of difficulty breathing, a headache, or that his or her chest hurts. Examples of symptoms include pounding heartbeat or feeling cold.

The difference between Signs and Symptoms--objective vs subjective--can be illustrated simply by the concept of fever:

• the patient may say he has fever because he feels hot--THIS IS A SYMPTOM;
• you take his temperature and it is 101.2°F--THIS IS A SIGN.

Past Medical History

Past medical history should include the general state of the patient's health including

• current medications and allergies,
• childhood and adult illnesses,
• accidents and injuries,
• previous surgeries or hospitalizations,
• physical disability due to previous illness or injury, and
• emotional status.

Family History

Family history should be obtained concerning similar symptoms and risk factors associated with prevalent disease in the blood line or family.

Personal Social History

Personal social history should be obtained as it relates to illness risk factors including but not limited to:

• smoking,
• drinking,
• drug use and abuse,
• diet, and weight loss or gain,
• sexual habits,
• occupation,
• environment, and
• travel.

Pediatric and Geriatric Patients

Along with the history-taking of pediatric patients, EMS providers should

• assess the infant pulse at the brachial artery,
• utilize capillary refill to reliably assess adequate blood flow or perfusion (in children six years old or younger), and
• use distracting measures to gain trust.

The history may require supplementary additions by the parent(s) or care-giver. (See pediatrics in special patient populations.)

Along with history-taking of geriatric patients, you should make sure to obtain eyeglasses and hearing aids if used and expect a lengthy history that may take some time and require redirection. (See geriatrics in special patient populations)