Family medical history is a record of diseases and illnesses that a patient's direct blood relatives have had. The record should go as far back as can be accurately traced, preferably for at least several generations. This history can be thought of as a medical family tree because the genetic relationship between individuals as well as their health information is important. Family medical history is crucial in assessing an individual's risk for many different diseases that are thought to have a genetic cause.
For instance, early onset familial Alzheimer's disease is an inherited disorder that involves a gene called ApOE. The gene may be inherited from either the mother or father. Symptoms of this type of Alzheimer's disease develop before age 65. Not everyone with the inherited gene will develop the disorder. The risk factor for early onset familial Alzheimer's disease is just higher for people with the ApOE connection in their family medical history.
It's estimated that about 5 to 10 percent of cancers are inherited. When genetic testing for cancer is done, the DNA of families that have had many members develop the disease over several generations is studied for patterns. A family medical history of cancer and the studied patterns of the disease in families can help doctors decide what kinds of tests patients should have and when they should have them. For example, if the suggested screening age for a certain type of cancer is 60, but a patient's medical history shows a genetic pattern of the disease, the physician is likely to decide that the individual should be screened at a much younger age.
It should be noted that piecing together a family medical history can be difficult in some cases. For instance, a history of alcoholism in a family may be downplayed or not revealed due to embarrassment or a reluctance to bring up the subject. Family medical histories must usually be done by speaking to blood relatives. If the relatives realize the importance of understanding genetic patterns through generations of a family in order to help prevent disease, they're often more likely to reveal the private medical information. Most people also feel it's important for couples having children to know their risks of passing on an inherited condition to their offspring.
Family medical history is a relevant part of a patient's health records, but it's important to remember that as helpful as it may be is assessing risks for different diseases, it's still only one part of determining a patient's possible future health. Exposure to certain chemicals as well as a person's weight, diet and exercise habits can lower or raise the risk of disease. For example, many people are genetically disposed to type 2 diabetes, but not all of these individuals will necessarily develop the disease. Studies have shown those at risk for type 2 diabetes may be able to avoid it through proper eating and exercise.