[Overview] The third lumbar transverse process syndrome is a common low back pain or low back and hip pain disease, which is a syndrome of low back and hip caused by acute and chronic injury to the muscles, tendons, ligaments and fascia attached to the third lumbar transverse process after congestion, edema, aseptic inflammation, adhesion, degeneration and scar contracture, which stimulates the lumbar spinal nerve. The detailed pathogenesis is not clear, but it is a common painful soft tissue disease. The diagnosis of this disease is mainly based on symptoms and signs, and requires a detailed medical history and a rigorous physical examination, otherwise it is easy to miss and misdiagnose. Etiology】 The third lumbar vertebra is located in the center of the lumbar spine and has the greatest mobility. The transverse processes on both sides are long, and the transverse processes have the beginning of the psoas major and psoas square muscles, and the deep fascia of the transversus abdominis and latissimus dorsi muscles are also attached to them. When the muscles of the lumbar region and abdomen contract strongly, this area is subjected to the greatest force, which easily leads to lacerations of the attached muscles and fascia, and the aseptic inflammation stimulated by the injury causes fibrous degeneration of the local muscles, fascia and nerves, resulting in the third lumbar transverse process syndrome. The posterior branch of the 1st to 3rd lumbar nerve crosses the fascia of the transverse process and travels dorsal to the transverse process. When the muscles and fascia attached to the transverse process are injured and adhesions and scar formation occur, the nerve can be impinged, causing pain in the lumbar region or lumbar hip region. Pathology】 The muscles and fascia attached to the transverse process of the third lumbar vertebra are edematous, hemorrhagic, and exuding due to acute or chronic injury, and after the injury is repaired, these tissues scarify and tissue proliferate. After microscopy, lymphocyte infiltration, thickening of the wall of small blood vessels, and nerve degeneration with calcium salt deposits within the soft tissue are seen. Clinical symptoms] This disease is common in young adults, most patients have a history of lumbar sprains, which is related to the wide range of lumbar activities and weight-bearing, especially when frequently bending or sudden lumbar sprain movements are more likely to occur. The main clinical symptom of this disease is lumbago or lumbar hip pain, most of them appear unilaterally, but there are also a few patients with bilateral onset. The degree and nature of pain varies, and the pain increases when bending and rotating the back. The pain is mostly persistent. In severe cases, the patient cannot lie on his back and has difficulty in turning and walking, but the pain is not affected by coughing or sneezing. A small number of patients may have intermittent claudication. The effect of oral drug treatment is not obvious. [Signs] There is obvious limited pressure pain at the tip of the transverse process of the third lumbar vertebra with fixed localization, which is the characteristic of this syndrome. The pressure pain can radiate to the buttocks and thighs, but the radiation bias does not exceed the knee joint. In long-standing patients, gluteal muscle atrophy may be present, and in long and thin patients, active muscle spasm nodules may be palpable at the tip of the transverse process of the third lumbar vertebra. The straight leg raise test may be positive, but the strengthening test is negative. Diagnosis] The diagnosis can generally be established based on clinical symptoms and physical signs. For a few patients who are difficult to diagnose, a diagnostic injection of lidocaine at the tip of the transverse process of the third lumbar vertebra can be made, and the diagnosis can be confirmed if the pain disappears immediately. This disease needs to be differentiated from lumbar disc herniation, acute lumbar sprain, pear-shaped muscle syndrome, and gluteal epicutaneous nerve entrapment syndrome. 【Treatment】 Application of corticosteroids such as prednisolone acetate, tretinoin, etc. for closure of the tip of the transverse process of the third lumbar vertebra can cure this disease. The treatment methods such as tui na, acupuncture and small acupuncture can also obtain satisfactory results. For non-surgical treatment is ineffective, the third lumbar vertebral tip release surgery is feasible, and can be performed under discoscopy in hospitals with conditions.