Medical history: Compiling your medical family tree. Your family medical history provides insight into the conditions that are common in your family. Use this history to give you clues about your risk of disease.Your family medical history, sometimes called a medical family tree, is a record of illnesses and medical conditions affecting your family members. family medical history can reveal the history of disease in your family and allow you to identify patterns that might be relevant to your own health. Your doctor might use your family medical history to: 1  Assess your risk of certain diseases.