Lymphoma is a type of cancer that originates in the lymphatic system, a key part of the immune system that includes lymph nodes, spleen, thymus, and bone marrow. It develops when lymphocytes, a type of white blood cell, grow and multiply uncontrollably. There are two main categories: Hodgkin lymphoma and non-Hodgkin lymphoma, which differ in their cellular characteristics and patterns of spread. Common symptoms may include painless swelling of lymph nodes, persistent fatigue, unexplained fever, night sweats, unintended weight loss, and itching. Lymphoma can affect individuals of any age and may involve multiple areas of the body. Diagnosis typically requires imaging studies and biopsy of affected lymph nodes or tissues to determine the specific type and extent of the disease.