| Term | Definition |
| acquired immunodeficiency syndrome (AIDS) | defect in the cellular immunity, the virus attacks lymphocytes and destroys them, resulting in an inability to fight infection |
| AIDS- related complex (ARC) | early stages of AIDS |
| allergies | disorder from overreaction of the immune system to an antigen or allergen |
| anaphylactic | life threatening severe allergic reaction |
| autoimmune disorders | hypersensitivity in which the body reacts against its own antigens |
| edema | excessive fluid in the tissues causing swelling |
| elephantiasis | inflammation, obstruction, and destruction of lymph vessels |
| Epstein-Barr virus | virus thought to cause mononucleosis |
| hepatits B | inflammatory disease of the liver caused by the hepatitis B virus |
| Hodgkin's disease | cancer of the lymphatic cells found in the lymph nodes |
| lymphadenitis | inflammation of the lymph glands |
| lymphadenopathy | enlargement of the lymph nodes |
| lymphangioma | benign mass in the lymph vessel |
| lymphangitis | swelling of the lymphatic vessel due to inflammation |
| lymphedema | abnormal collection of lymph fluid usally found in the extremities |
| lymphopenia | decreased number of lymphocytes |
| malignant lymphoma | cancerous tumor of lymphatic tissue |
| mononucleosis | acute infectious disease with a large number of atypical lymphocytes |
| non-Hodgkin's lymphoma | cancer of the lymphatic tissue other than Hodgkin's |
| organ rejection | rejection of transplanted tissue as a foreign tissue by the immune system |
| peritonsillar abscess | infection of the tissues between the tonsils and the pharynx |
| pneumocystis carinii pneumonia | pneumonia common in AIDS patients caused by infection with a parasite |
| sarcoidosis | inflammatory disease of the lymph system which may cause lesions |
| splenomegaly | enlargement of the spleen |
| systemic lupus erythematosus | chronic autoimmue disorder of connective tissue |
| thymoma | malignant tumor of the thymus gland |
| tonsillitis | inflammation of the tonsils |
