Unseen swollen lymph nodes may also be cancerous, as many early stage cancer patients do not have swollen lymph nodes. Cancer is a common malignant disease, which is more likely to have lymph node metastasis, thus causing swollen lymph nodes. However, many early-stage cancer patients do not have lymph node metastasis, so they usually do not have enlarged lymph nodes. Therefore, cancer cannot be ruled out simply by the absence of enlarged lymph nodes, and further examinations should be carried out in order to avoid under-diagnosis of early-stage cancer. It is recommended that people with high risk factors for tumors maintain good dietary and living habits, appropriate exercise, and regular medical checkups for early detection of diseases and early treatment, so as not to affect the survival period.