Swollen or painful lymph nodes in the thigh are more likely to be caused by inflammation, especially cellulitis of the lower extremities, or thrombophlebitis combined with varicose veins, simple lymphangitis can lead to enlarged lymph nodes, and the patient may also have pain or even fever. In this case, anti-inflammatory treatment should be systematically administered, and the most common drug is sodium penicillin, which needs to be given twice a day. If there is significant swelling in the limb, you can also choose to apply local magnesium sulfate topically to elevate the limb and promote venous blood return, which can also relieve the patient’s discomfort. During the treatment period, patients should also be advised to pay attention to rest, not to strain and avoid excessive walking, which should also lead to the aggravation of lower limb swelling. In the case of thrombophlebitis, further surgical treatment options are required if necessary.