World Lymphoma Awareness Day, started by the Lymphoma Coalition in 2004, is observed on September 15 to raise awareness about lymphoma and the lymphatic system. Lymphoma is a blood cancer affecting lymphocytes, a type of white blood cell; its two main forms are Hodgkin and Non-Hodgkin lymphoma. The lymphatic system includes lymph nodes, spleen, thymus and bone marrow. Typical symptoms are painless swollen lymph nodes, fever, night sweats, fatigue and unexplained weight loss. The 2026 theme is “Navigating Lymphoma and Chronic Lymphocytic Leukaemia (CLL) Together.”