The causes of inexplicable thigh pain and soreness include the following: First, consider the thigh pain and soreness caused by strain on the soft tissue of the thigh muscles, mostly due to heavy physical labor, or recently engaged in physical exercise, resulting in strain on the thigh muscles, which causes lactic acid accumulation, resulting in pain and soreness in the thigh, through rest and with hot compresses, massage, physiotherapy, etc, Through rest and with hot compress, massage, physiotherapy, etc. can significantly relieve the symptoms. Second, consider is due to the body lower extremity venous reflux, and then cause thighs sore, sore, etc., mostly due to the body long-term standing or venous valve insufficiency and other causes of blood can not return, and then cause the lower extremity blood reflux, resulting in the lower extremity thighs inexplicably pain, sore, etc., need to go to the hospital to do lower extremity vascular ultrasound examination to clarify, at the same time usually pay attention to minimize the long time standing, when resting The lower limbs can be properly elevated to promote blood flow back to the lower limbs.