There are more clinical reasons for hip pain, and the most common disorders are the following: 1. Sciatica caused by lumbar disc herniation occurs in lumbar 4 and 5, and lumbar 5 sacral 1 disc degeneration and herniation, and the inflammatory substances released stimulate or compress the nerve roots, resulting in sciatica. The pain occurs in the lumbosacral region, buttocks, thighs, and can even radiate to the calves. Therefore, hip pain should be excluded from sciatica caused by lumbar disc herniation.2. Hip pain may be related to pyromyelitis gravis, an unexplained inflammatory edema of the pyromyelus muscle, which can also cause hip pain by compressing the sciatic nerve.3. Hip impingement syndrome, when the abnormal development of the femoral head and neck mismatch, long-term hip flexion leads to the impact of the femoral head and neck with the glenoid lip of the acetabulum, resulting in glenoid lip injury, which can be clinically manifested as the inguinal region or the calf. When hip pain occurs, hip impingement syndrome should be excluded. 4. Femoral head necrosis, early femoral head necrosis can be manifested as hidden pain in the inguinal region and hip, but in the middle and late stages, the pain in the inguinal region and hip will be significantly increased. When there is pain in the left hip, it is necessary to distinguish it from the above-mentioned disorders.