Lymphatic tissue hyperplasia, a reactive proliferation of lymphocytes and histiocytes in the lymph nodes caused by injury or stimulation from various causes, resulting in enlarged lymph nodes, is called lymph node reactive hyperplasia. There are many causes, including bacteria, viruses, toxins, toxic products of metabolism, denatured tissue components and foreign bodies, all of which can act as antigens or allergens to stimulate lymphatic tissues to cause reactions. The composition and distribution of microscopic lymph node reactive hyperplasia vary depending on the causative agent. Antigenic substances that stimulate B cells mainly cause enlarged lymphoid follicles and enlarged hyperplasia of germinal centers. Antigenic substances that stimulate T cells mainly cause proliferation of lymphocytes in the parafollicular area. Some antigenic substances cause proliferation of histiocytes mainly in the lymphatic sinus. Lymph node reactive hyperplasia is a benign lesion, but swollen lymph nodes can easily be confused with tumors of the lymph nodes, either by visual or microscopic view, so it is important to make a good differential diagnosis when treating them. The main types of lymph node hyperplasia are: the first is non-specific reactive lymphoid follicular hyperplasia. The second is giant lymph node hyperplasia. The third is vascular immunoblastomatous lymphadenopathy.