The intervertebral disc is located in the middle of the two vertebrae, like a ‘soft cushion’, the vertebrae are closely connected to play a role in stabilizing the joint and cushioning shock, to better protect our spine. To use an analogy, the intervertebral disc is like a flat meat bun, the fibrous ring is the skin of the bun, the nucleus pulposus is the filling. People are upright walking animals, so the intervertebral disc will be subject to long-term vertical compression from gravity. Due to aging, trauma, congenital deformity or certain triggering factors (pregnancy, bending over and bearing weight, cold, etc.), the ‘soft cushion’ will be constantly worn, and the first to be damaged is the outer fibrous ring (bun skin), which will be constantly deformed and even ruptured. If the bun is just flattened, the skin is not broken, the filling does not leak out, this situation is the disc bulge; if you continue to press this bun, the bun skin broke, the filling inside leaked out part of the disc, this situation is a herniated disc; if you continue to be pressed, the filling inside will fall out, this situation is the disc prolapse. Once the filling of the bun in the lumbar spine leaks out and compresses the spinal cord, nerves and other important tissues, symptoms such as back pain, leg pain or numbness, intermittent claudication, and even urinary and fecal disorders may occur, and it becomes a disease – lumbar disc herniation, which seriously affects daily life.