Does ancestry determine disease risk? Can genetic testing really improve your health? Or does discovering a disease-causing mutation in your genome just give you something else to worry about?

Those are the questions I confront every day in my genetics practice. When people ask me about the value of genetic testing, I tell them that knowing your risk for disease, along with your family history, can make all the difference in choosing the best plan of action for your healthcare and that of your family.

Your family's medical history is a summary of health information gathered from three generations of relatives, including siblings, parents, aunts, uncles, grandparents and children. Patterns of inherited diseases and disorders, whether common (such as heart disease) or uncommon (such as collagen disorders), can be identified by analyzing this history.

This helps us identify family members who are at an increased risk of developing disease. Empowered by this information, you and your doctor can then take steps to reduce your risk.

Say that someone is known to have an increased genetic risk of breast or colorectal cancer. The physician may order more frequent screenings or start screening tests at an earlier age than is usually indicated.

Many of us are born with genetic mutations, some of which put us at an increased risk of developing various diseases during our lifetime. However, these mutations merely bring risk of disease, not a guarantee of a death sentence. The interplay between genes and environment is very powerful, and your physician will use information about both your genetics and lifestyle to try to prevent, circumvent or minimize your risk of developing a disease.

Fortunately, doctors have many tools to help filter your personal information out of our collective cultural melting pot. Once your doctor has all your information, he or she can help identify whether you are at an increased risk for a given condition. At this point, a geneticist or genetic counselor can conduct more detailed testing.

It is important that this delicate, detailed path be navigated by a genetics expert. The Internet is riddled with online genetic kits that promise to expose the medical secrets hidden within your cells. Unfortunately, without the involvement of a professional, such tests may only provide unwanted, unfounded or unreliable results that cause needless worry.

Genetic counseling starts with the careful gathering of information and potentially ends with the revelation of increased or decreased susceptibility to developing a given genetic condition. What happens in between these two points may be both challenging and empowering, but it is most certainly a journey worth traveling.

Dr. VALENTINA DALILI is board certified in internal medicine and medical genetics and is a member of Hoag Medical Group.