Lumbar disc herniation refers to a series of symptoms caused by a herniated nucleus pulposus of the lumbar disc compressing its surrounding nerve tissue. So what are the routine tests for lumbar disc herniation? 1.CT scan: this diagnostic method can effectively show the performance of lumbar disc herniation, experts proposed: scanning lumbar disc herniation has 4 kinds of performance: 1) the fat layer between the spinal canal and the dural sac disappears, which is the earliest performance. 2) the herniated disc block shadow appears in the spinal canal, its CT value is lower than the bone but higher than the dural sac. 3) the nerve root is pushed and displaced. 4) the dural sac is deformed by pressure. The correct rate of CT diagnosis is about 90%. 2. X-ray examination: it can be clear unless some symptoms, patients with disc herniation, indirect signs such as scoliosis of the spine, lumbar convexity becoming flat, unequal height of the vertebral space left and right or narrowing of the front and back and narrowing of the vertebral space can be seen in lumbar spine plain film examination. In addition to being a reference for routine examination of patients with lumbar disc herniation, it can also exclude septic inflammation, tuberculosis, tumor and mutation of the lumbar spine. 3. MRI examination: It can clearly show the lesions in the spinal canal. MRL is a non-invasive examination that uses atomic nuclear magnetic phenomenon imaging, which in the human body is currently mainly based on the change of hydrogen nucleus protons in the magnetic field as the signal source. Different tissues in the body have different water content, which means that the signal on them is different. Soft tissues with high water content have a higher signal than tissues with low water content such as ligaments and bones. 4. Myelography: It is used for the examination of the complications of lumbar disc herniation. Through lumbar puncture, fat-soluble iodine or water-soluble iodine is injected into the subarachnoid space, and then a dynamic x-ray examination is performed. Because of the invasive examination and the use of contrast agents have certain adverse reactions, attention should be paid to the prevention and control of complications when applying this examination. Electromyography: Electromyography can record the bioelectrical activity of nerve muscles to determine the functional state of the nerve muscles, thus helping to diagnose motor neuromuscular disorders. Electromyography has unique value in the diagnosis of nerve root compression. By measuring the electromyography of the muscles innervated by different segments of the nerve root, the damaged nerve root is determined according to the extent of the abnormal myopotential distribution. Then, from the relationship between the nerve root and the intervertebral foramen, the site of nerve compression can be inferred. Lumbar disc herniation is relatively common in daily life and its harmfulness is also great, so the examination method for it is something we must understand, because only if we understand it clearly, we can find it early and treat it early.