| A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors. For example, exposing skin to strong sunlight is a risk factor for skin cancer. Smoking is a risk factor for cancers of the lung, mouth, larynx, bladder, kidney, pancreas, and several other organs. But risk factors don't tell us everything. Having a risk factor, or even several, does not mean that you will get the disease. Likewise, not having any known risk factors doesn't mean you won't get the disease. Scientists have found a few risk factors that may make a person more likely to develop Hodgkin disease, although it's not always clear why these factors increase risk. Epstein-Barr Virus (EBV) Infection/Mononucleosis There is an increased risk of Hodgkin disease in people who have had infectious mononucleosis (sometimes called "mono" for short), an infection caused by the Epstein-Barr virus. The risk of developing Hodgkin disease in people who have had infectious mononucleosis appears to be a few times higher than in people who have not had the disease, although the overall risk is still very small. The Epstein-Barr virus is found within the DNA of Reed-Sternberg cells in about half of all patients with Hodgkin disease. But the other half of patients with Hodgkin disease have no evidence of Epstein-Barr virus in their cancer cells. Age Hodgkin disease is most common in early adulthood (age 15 to 40, especially in a person's 20s) and in late adulthood (after age 55). Gender Hodgkin disease occurs slightly more often in males than in females. Geography Hodgkin disease is most common in the United States, Canada, and northern Europe, and is least common in Asian countries. Family History There is a higher risk for Hodgkin disease in brothers and sisters of young people with this disease. The risk is very high for an identical twin of a person with Hodgkin disease. But a family association is still uncommon, and accounts for only around 5% of all cases. It's not clear why family history might increase risk. Some families may have a higher rate of Hodgkin disease because of similar early childhood exposures to infections (such as Epstein-Barr virus), inherited genes that make them more susceptible, or some combination of these factors. Some researchers have found certain changes in the genes responsible for immunity in patients with Hodgkin disease. Socioeconomic Status The risk of Hodgkin disease is greater in people with a higher socioeconomic background. | 
