Lymph, also known as lymphatic fluid, forms the lymphatic system with lymphatic tissues, lymphatic vessels and lymphatic organs. The lymphatic system is similar to the blood circulation system and is basically located in all organs of the body. One of the largest lymphatic organs is the spleen organ, which helps filter blood as well as reserve excess blood. The main role of the lymphatic system is to fight against the invasion of viruses and bacteria, and it plays an important role in the immune function of the body. In daily life, when the body is invaded by viruses or bacteria, the lymphatic system will automatically activate the immune function to fight. Only when the body fights against germs will symptoms appear, such as swelling of the lymph and pain. If the lymph nodes are swollen and painful, it means that there is a virus or bacteria invasion, so you should go to the hospital in time to investigate the cause. If only the lymph nodes are swollen and there is no obvious pain, there is no need to worry too much and most of them can recover by themselves. Third, if the normal structure of the lymph nodes is destroyed, resulting in the proliferation of lymphocytes, attention should also be paid to such diseases, most of which are caused by malignant lymphatic diseases.