Sitting for a while legs numb, there are mainly the following reasons lead to:1. Patients have lumbar disc herniation compression of the nerves lead to numbness of the legs.2. Patients have problems with the veins or arteries of the lower limbs lead to numbness of the legs.3. Patients’ lower limbs, such as the thigh nerves have some lesions, leading to the impairment of the nerve function of the legs, which may lead to numbness of the legs.4. Patients may have some neurological diseases, such as obsessive-compulsive disorder, depression, etc. own subjective feeling of feeling numbness in the legs, but in fact there is no substantial disease.