Lymph node abnormality is not necessarily cancer, and there are many reasons for lymph node abnormality, which are as follows: 1. Infection of pathogens: the more common reasons, such as upper respiratory tract infections, including pharyngitis, tonsillitis, periodontitis, etc., can cause enlarged lymph nodes in the neck. Viral infections, the more common ones are EB virus and cytomegalovirus, which can also cause generalized lymph node enlargement; 2. Malignant tumors: including lymphoma, or metastasis of solid tumors in other parts of the body, such as lung cancer, gastric cancer, etc., which can be metastasized to cervical or supraclavicular lymph nodes and cause lymph node enlargement. Lymph node enlargement caused by lymphoma or metastatic cancer is usually painless, which is different from lymph node enlargement occurring in infection; 3. Non-infectious diseases: such as necrotizing lymphadenitis, and autoimmune diseases, which can present with lymph node enlargement. Lymph node abnormalities can be manifested as subcutaneous lymph node enlargement, the patient can touch the mass, and sometimes there can be pressure pain. In the case of bacterial infections, patients may also experience redness, swelling, heat, and pain on the surface skin. When patients have enlarged lymph nodes, they should be further examined and, if necessary, a lymph node biopsy should be done so as to clarify the cause of the enlarged lymph nodes.