Lymph node pain at the root of the thigh may be caused by lymphangitis of the lower limbs, tumor diseases and other reasons. 1. Lower extremity lymphangitis: lower extremity lymphangitis is mainly a soft tissue infection caused by trauma, or the patient has a history of athlete’s foot, which can also be secondary infection of lower extremity lymphangitis, and the patient will have obvious thigh root lymph node pain and fever. 2. Tumor lymph nodes: one of the metastatic pathways of malignant tumors is lymphatic metastasis. Primary malignant tumor cells are transferred to lymph nodes through lymphatic fluid, which will cause lymph node canal blockage and lymph node enlargement, necrosis and other symptoms, and then the symptoms of pain will appear. Malignant tumors such as osteosarcoma of the lower extremity will show obvious symptoms of lymph node pain at the root of the thigh. Lymph node pain at the root of thigh is also seen in other causes, it is recommended to go to the hospital in time for examination and diagnosis, and under the guidance of the doctor to carry out the correct treatment, so as not to delay the condition.