Knowing your family history is Habit #3 of our Five Healthy Lifestyle Habits to Reduce Cancer Risk. Family health history is your biological family’s record of illnesses. Having an understanding of your family’s health history can be beneficial for knowing potential health threats.

One of the main factors of your family health history is your genetic makeup. Cancer is caused by gene mutations that affect how cells function (National Cancer Institute). Five to 10 percent of all cancers are caused by inherited genetic defects, or “hereditary cancer syndromes,” that have been passed down the family tree (The American Cancer Society). You can learn about the more common hereditary cancer syndromes that can be discovered through genetic testing by clicking here.

Although there’s nothing you can do to change your genetic makeup, knowing about it can help you and your doctor decide which cancer screening tests you need and when you should start getting screened. Your doctor will likely recommend you undergo genetic testing if the following three circumstances are all true (National Cancer Institute):

1. You or your family history shows a likely chance of a hereditary cancer syndrome.
2. The results of the test will be able to clearly tell whether or not a genetic mutation is present.
   
3. The results of the test will be able to provide insight that will assist in your future medical care.
   

Your family health history includes more than just shared genes. It also includes shared lifestyle habits. For example, according to a U.S. News article highlighting research from Georgetown University’s Lombardi Comprehensive Cancer Center, “the longer children are exposed to the behavior of a parent addicted to smoking, the more likely they are to start the habit themselves and become a heavy smoker in the future.” We know from Habit #1 – Avoid Tobacco – that smoking can cause cancers including acute myeloid leukemia and cancer of the bladder, cervix, colon, esophagus, kidney, larynx, liver, lung, mouth, pancreas, stomach and throat. Therefore, if cancer seems to “run in your family,” it may be caused by shared lifestyle habits as opposed to an inherited gene mutation.

Knowing your family health history is an important step toward a cancer-preventive lifestyle. Genes shared with family members cannot be changed, however, alleviating poor lifestyle habits such as smoking, lack of exercise, and an unhealthy diet can help decrease your risks.