The presence of lymph nodes larger than 3 cm is not necessarily cancer. There are many reasons for enlarged lymph nodes, and benign diseases such as local inflammation can also cause them. Therefore, the diagnosis of cancer cannot be based on the size of lymph nodes alone, but also requires relevant examinations to look at the blood supply, structure and other parts of the lymph nodes, etc. for a comprehensive judgment. If the cervical lymph nodes are swollen with redness, swelling and pain, the first thing to consider is inflammatory conditions such as cold, pharyngitis, lymphadenitis, etc. The lymph nodes are involved in the body’s immune response and appear swollen. Patients can take antibiotics and observe for a period of time. If the lymph nodes gradually shrink, it is indicated that it is caused by infections such as colds. In addition, patients with chronic rhinitis may also show enlarged cervical lymph nodes for a long time; varicose veins of lower limbs with skin infection may show enlarged lymph nodes in the groin area. The swollen lymph nodes may also be one of the manifestations of cancer, such as tumor metastasis, lymphoma, etc., which usually manifests as painless enlargement and therefore needs to be differentiated. It is recommended that patients who have swollen lymph nodes for a longer period of time should promptly visit the corresponding departments of the hospital, such as the department of quintuplegia and surgery, and undergo lymph node aspiration, ultrasound and other examinations to identify them.