Emergency Department Training

Chief Complaint and History of Present Illness

A chief complaint (CC) is a concise statement that describes the symptom, problem, condition, diagnosis, or reason for the patient encounter. The CC is usually stated in the patient’s own words.

History of the present illness (HPI) is a chronological description of the development of the patient’s present illness from the first sign and/or symptom or from the previous encounter to the present.

Review of Systems

Review of Systems (ROS) is an inventory of body systems obtained by asking a series of questions in order to identify signs and/or symptoms that the patient may be experiencing or has experienced.

The following 14 systems are recognized:















Past, Family, and/or Social History (PFSH)


  • Past history including experiences with illnesses, operations, injuries, and treatments.


  • Family history including a review of medical events, diseases, and hereditary conditions that may place the patient at risk.


  • Social history including an age appropriate review of past and current activities.

PFSH consists of a review of three areas:


An examination may involve several organ systems or a single organ system. The type and extent of the examination performed is based upon clinical judgment, the patient’s history, and nature of the presenting problem(s).

The following organ systems are recognized:

Constitutional              Genitourinary

Eyes                              Musculoskeletal

ENMT                           Skin

Cardiovascular             Neurologic

Respiratory                   Psychiatric

Gastrointestinal           Hematologic/lymphatic/immunologic


Medical Decision Making (MDM)

The levels of E/M services recognize four types of medical decision making (straight-forward, low complexity, moderate complexity, and high complexity). Medical decision making refers to the complexity of establishing a diagnosis and/or selecting a management option as measured by:

1. The number of possible diagnoses and/or the number of management options that must be considered;

2. The amount and/or complexity of medical records, diagnostic tests, and/or other information that must be obtained, reviewed, and analyzed; and

3. The risk of significant complications, morbidity, and/or mortality, as well as comorbidities associated with the patient's presenting problem(s), the diagnostic procedure(s) and/or the possible management options.

Critical Care

Critical care involves high complexity decision making to assess, manipulate, and support vital system functions(s) to treat single or multiple vital organ system failure and/or to prevent further life threatening deterioration of the patient’s condition.

Examples of vital organ system failure include, but are not limited to: central nervous system failure, circulatory failure, shock, renal, hepatic, metabolic, and/or respiratory failure.

Critical care is usually, but not always, given in a critical care area such as a coronary care unit, intensive care unit, respiratory care unit, or the emergency department.