A lymphoma is a type of cancer that affects the lymph system, which is part of the body's immune system. The two main types of lymphoma are Hodgkin's lymphoma and non-Hodgkin's lymphoma.

Lymphomas are more common in men than in women. In most cases the cause is not known. Symptoms of lymphoma include swelling in one or more groups of lymph nodes, weakness, fever, weight loss, and an enlarged liver and spleen.

Depending on the type of lymphoma and whether it is confined to a single group of lymph nodes or affects many lymph nodes, treatment may include radiation therapy, chemotherapy, or, in serious cases, a stem cell transplant. Because the disease and its treatment impair the immune system, a person who has lymphoma has an increased risk of dying from infection.