Lymph is usually divided into lymphatic vessels and lymph nodes. In the case of lymphatic lesions, there are two conditions: First, lymphatic vessels appear lesions. For example, if the lymphatic vessels are inflamed by bacterial infection, there will be widespread redness, swelling and pain in the soft tissues near the inflamed lymphatic vessels, and in severe cases, there will be generalized fever. If the lymphatic vessels are blocked or damaged, the limbs at the location of the damage will show depressed edema. Second, lesions of lymph nodes, mostly caused by inflammation or tumor metastasis, usually manifest as abnormal enlargement of lymph nodes. If it is benign, the boundary is usually clearer, pressure will be painful, and the mobility is higher. If it is a malignant tumor cell metastasis, the boundary is not very clear and irregular in shape, and it is rarely more mobile.