In medicine, a family history consists of information about disorders that a patient's direct blood relatives have suffered from. Genealogy typically includes very little of the medical history of the family, but the medical history could be considered a specific subset of the total history of a family.

Uses

Although often neglected (Rich et al 2004), many doctors glean information on family morbidity of particular diseases (e.g. cardiovascular diseases, autoimmune disorders, diabetes, cancer) to appreciate whether a person is at risk for developing similar problems.

Family histories may be imprecise because of various possible reasons:

• Adoption or illegitimacy
• Lack of contact between close relatives
• Uncertainly about the relative's exact diagnosis

In complex situations, a family tree may be necessary to cover the necessary aspects.

Consequences

Not all positive family histories imply a genetic cause. If various members of the same family have been exposed to the same toxin, then they may develop similar symptoms without a genetic cause.

If a patient has a strong family history of a particular disorder (or group of disorders), this will generally lead to a lower threshold for investigating symptoms.

In diseases with a known hereditary component, many healthy people are now tested early to prevent the symptoms from developing. This has become accepted in cystic fibrosis, hemochromatosis and various other disorders.

Reference

• Rich EC, Burke W, Heaton CJ, Haga S, Pinsky L, Short MP, Acheson L. Reconsidering the family history in primary care. J Gen Intern Med 2004;19:273-80. PMID 15009784.