Lymphomas are cancers of the lymph system. The lymph system includes the lymph nodes, or lymph glands, which are located throughout the body, the tonsils, adenoids, thymus and spleen. Lymphomas are a diverse group of diseases. They include Hodgkin's disease and non-Hodgkin's disease. Often, the first symptom of lymphoma is enlargement of lymph nodes with no other obvious symptoms. Swelling of the lymph nodes, which are normally the size of a bean, is not necessarily a sign of lymphoma; many other conditions can cause nodes to enlarge. However, if your glands stay swollen for more than two weeks, consult a physician. Other symptoms include decreased appetite, weight loss, fever, itching, night sweats, and pressure and pain in the lower back. These symptoms may be common to many illnesses, but should be checked by a doctor if they persist for more than two weeks. Some emergency symptoms of lymphomas, which require immediate medical attention, include the sudden onset of high fever from any cause; loss of, or change in bladder or bowel control; numbness or loss of strength in the arms and legs; and mental confusion and drowsiness. The risk factors for lymphomas are largely unknown, but they do involve reduced immune function and exposure to certain viruses. Persons with organ transplants are at higher risk due to altered immune function. Other possible risk factors include exposures to herbicides, industrial solvents, and vinyl chloride. For more information on lymphomas, talk with your healthcare provider.