Hodgkin's lymphoma is a type of cancer that affects the lymphatic system, which is part of the body's immune system. It occurs when certain white blood cells, called lymphocytes, grow uncontrollably. This can lead to swollen lymph nodes, fever, weight loss, and night sweats. Hodgkin's lymphoma is generally considered one of the more treatable forms of cancer, especially when diagnosed early. The exact cause of Hodgkin's lymphoma is not known, but it can occur in people of any age, though it is most common in young adults and those over 55. Treatment often involves chemotherapy, radiation therapy, or a combination of both, and many patients can achieve remission.