When you go to the doctor for a check up why does the doctor ask if there is family cancer or heart disease?

Detective work: Think of your doctor as a medical detective. She/he is trying to learn all about what might be harmful to you. Your symptoms, if any, are important. So is physical exam. Laboratory tests are expensive and need to be directed. A powerful clue to what needs special attention now & in the future is what happened to your immediate family members. Heart disease and cancer are the 2 biggest killers.

To assess risk.: When you get a check-up from your doctor, you may be asked questions about illnesses that run in your family. Your doctor is trying to assess whether your family's health history puts you at risk for any diseases or health factors that run in the family.

Guide risk history: Family history of disease may indicate there is a hereditary component to the disease, especially if there are several aunts, uncles, parents, grand-parents or siblings with the same disease. So, if there is a family history of a certain type of cancer, earlier screening for this disease can be implemented--instead of just "standard" care.