Even if you think that you don't have anything in common with your family members, you'll always share their genes. Sometimes, that means you have an increased risk of developing certain conditions and diseases. For example, if your parents have heart disease, you're more likely to develop it yourself. There can also be both genetic components and behaviors learned from your family. For example, if a parent was diagnosed with type 2 diabetes before the age of 50, you have a one in seven chance of getting it [source: American Diabetes Association]. Or you may have been taught poor eating and exercise habits when growing up, which can also lead to type 2 diabetes. Some types of cancer can also have a hereditary component, such as colon cancer.
If your doctor doesn't ask you about your family history and you're concerned that you may get a disease because a relative had it, bring it up yourself. The doctor may put your mind at ease. Remember that this doesn't mean you'll automatically get the disease or condition; you just have a higher likelihood of it. Ask your doc how you can lessen your risk through your behavior. It's important to be honest about your habits; if you drink or smoke, say so. Be honest about your exercise and stress levels. Men already have a higher risk of developing cancer and heart disease than women, but they're also more likely to make lifestyle choices that can increase that risk. Your doctor isn't there to judge but to help you be the healthiest that you can be. He or she can't do that without all of the information, so ask (and answer) away.