Medical history

The medical history or anamnesisof 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. The medically relevant complaints reported by the patient or others familiar with the patient are referred to as symptoms, in contrast with clinical signs, which are ascertained by direct examination on the part of medical personnel. 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.
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.