The exact cause of Hodgkin lymphoma is unknown. However, your risk of developing the condition is increased if: you have a medical condition that weakens your immune system you take immunosuppressant medication you've previously been exposed to a common virus called the Epstein-Barr virus – which causes glandular fever You also have an increased risk of developing Hodgkin lymphoma if a first-degree relative (parent, sibling or child) has had the condition.