At present, most doctors and patients believe that “it is the herniated disc that compresses the nerve and causes the patient’s back and leg pain, and the greater the herniated disc, the more severe the back and leg pain”. In the days when CT and MR imaging were not available, doctors and patients were convinced of this statement, and even more so with the availability of CT and MR imaging. Therefore, doctors and patients try every possible way to make the herniated disc disappear or shrink back through various treatments to eliminate the clinical symptoms of patients. Before we started CT-guided drug interventions, we also followed this theory to guide our work. However, in the past twenty years of clinical practice work, we found that there is a discrepancy between the fact and the theory. Due to the advantages and special features of our radiologists’ work, we receive dozens of patients who come for CT or MR examination of lumbar spine for low back pain every day. After surgery, although the clinical symptoms of low back and leg pain disappeared, the postoperative imaging performance was the same, and the herniated disc was still herniated and did not disappear because of the surgery. 2. Some patients with bulging discs in the imaging examination can have the same clinical symptoms of low back and leg pain as the herniated disc even though they do not see the herniated discs compressing the nerves. 3. Since we carried out CT-guided drug interventional therapy in 1993, many patients with herniated discs (including severely herniated discs or with free discs) that most doctors thought must be treated surgically have disappeared through interventional therapy, and their clinical symptoms of low back and leg pain have disappeared, but the patient’s discs are still found to exist in the imaging examination. 4. Some patients’ CT and MR imaging examinations show that the site of disc protrusion does not match the patient’s clinical symptoms; for example, the left side of the disc is protruding, but the radiating pain of the lower limbs is on the right side; or some patients have L5-S1 disc protrusion, but the clinical symptoms are caused by L4-5 disc lesion. Therefore, clinical practice tells us: 1. Patients with clinical symptoms of low back and leg pain can have disc protrusion on imaging (CT,MR); 2. Patients with disc protrusion on imaging (CT,MR) can have no clinical symptoms of low back and leg pain; 3. Patients who have no clinical symptoms of low back and leg pain should not worry about the herniated disc and do not need any treatment.