Leg pain due to a bulging lumbar disc is a very common clinical phenomenon. When a bulging lumbar disc develops, it compresses the nerve roots, which are an important part of the sciatic nerve, laterally and posteriorly. The sciatic nerve is composed of the lumbar plexus and sacral plexus, and the nerve roots compressed by a bulging lumbar disc belong to the lumbar plexus. Therefore, when the nerve root is compressed and produces aseptic inflammation and edema, the symptoms of sciatica will be triggered. Once the sciatic nerve is stimulated it will certainly produce symptoms of leg pain and numbness, so it is very normal for a bulging lumbar disc to cause leg pain, which can reach more than 90% clinically.