Low back pain with thigh pain is commonly caused by the following reasons: 1, the most common is a herniated lumbar disc, because the herniated disc compresses the sciatic nerve, the patient will produce symptoms of low back pain, and at the same time, the back of the thigh from the hip down the radiating pain, this situation should be resolved by rest, or lifting the compression of the disc pain symptoms. 2, sacroiliac joint problems, because the lumbar spine and lower limbs are connected by the sacroiliac joint, if the sacroiliac joint problems, the patient may also appear lumbar pain with thigh pain symptoms. 3, muscle problems, each person’s psoas muscle is connected to the pelvis through the waist, psoas muscle lesions will also appear lumbago with thigh pain. 4, lower limb muscle problems, such as the iliotibial bundle or bursitis around the hip joint can occur. Therefore, it is necessary to go to the hospital and have the doctor check what the cause of low back pain and thigh pain is at the same time.