Inflammation of lymph nodes, inguinal hernia, lumbar disc herniation, pyriformis syndrome, etc. may be the cause of groin discomfort and thigh soreness. 1. Lymph node inflammation: there are lymph node groups in the groin area, when infected by inflammation, the lymph nodes become swollen and painful, causing soreness around the groin. 2. Inguinal hernia: When there is an inguinal hernia, the hernia contents herniate out, causing discomfort in the inguinal area, and there will be pain after incarceration. 3. Lumbar disc herniation: the herniated disc tissue compresses the nerves, causing numbness, soreness and discomfort on the outer thighs, if necessary, do the CT examination of lumbar discs for diagnosis. 4. Piriformis syndrome: thigh pain and numbness caused by damage to the piriformis muscle, which presses the sciatic nerve. Appear groin discomfort, thigh pain, may also be a long time standing, overwork and so on, try to go to the hospital, let the doctor clear diagnosis and then treatment.