Patient history

The medical history or anamnesis of a patient is information gained by a physician or other healthcare professional by asking specific questions, either of the patient or of other people who know the person and can give suitable information (in this case, it is sometimes called heteroanamnesis), with the aim of obtaining information useful in formulating a diagnosis and providing medical care to the patient. This kind of information is called the symptoms, in contrast with clinical signs, which are ascertained by direct examination. Most health encounters will result in some form of history being taken. Medical histories vary in their depth and focus. For example an ambulance paramedic would typically limit their history to important details such as name, history of presenting complaint, allergies etc. In contrast, a psychiatric history is frequently lengthy and in depth as many details about the patients life are relevant to formulating a management plan for a psychiatric illness.

A physician typically asks questions to obtain the following information about the patient:


 * The name, age, height, and weight
 * The "chief complaint" &mdash; the major health problem or concern, and its history
 * Past medical history (including major illnesses, any previous surgery/operations, any current ongoing illness, eg diabetes)
 * Systematic questioning about different organ systems
 * Family diseases
 * Childhood diseases
 * Social status (including living arrangements), occupation, drug use (including tobacco, alcohol, other recreational drug use)
 * Regular medications (including prescribed by doctor, and others obtained over the counter)
 * Allergies
 * Sex life, obstetric/gynecological history and so on as appropriate.

The information obtained in this way, together with clinical examination, enables the physician to form a diagnosis and treatment plan. If a diagnosis cannot be made then a provisional diagnosis may be formulated, and other possibilities (the differential diagnosis) may be added, by convention listed in order of likelihood. The treatment plan may then include further investigations to try and clarify the diagnosis.

It may be comprehensive history taking (as practised only by medical students) or iterative hypothesis testing (as practised as rule of thumb by busy clinicians). Computerised history-taking could be an integral part of clinical decision support systems.