The causes of swollen lymph nodes can be both benign and malignant. Benign causes of enlarged lymph nodes commonly include viral infections, bacterial infections, parasitic infections, and so on. In addition, malignant diseases are mainly seen in lymph node metastases from tumors and diseases that originate in the lymphatic system, such as lymphoma. When comparing benign diseases with malignant diseases, there is a brief way to determine if the swollen lymph nodes are accompanied by significant pain, which is usually seen in benign rather than malignant diseases. Of course, this method of detection is not always accurate, and in order to clarify what kind of disease is causing the swollen lymph nodes, one should go to the hospital for appropriate tests, such as lymph node ultrasound and, if necessary, lymph node biopsy and pathological examination.