There are two main categories of internal and external causes: internal causes include degenerative lesions, cytokines, autoimmune, genetic factors, etc. The external causes are mainly trauma, pregnancy, occupation, habit, etc. Degenerative disease is commonly known as aging, as people grow older, the human lumbar disc will follow the aging. Injury means trauma, and it is inevitable that the lumbar spine will be affected by traumatic factors during a person’s lifetime, which accelerates the protrusion of the lumbar disc. Cytokines and autoimmunity are changes that occur microscopically in the body and should not be underestimated in the process of disc herniation. Genetic factors are of a familial nature, and immediate family members of patients with lumbar disc herniation are more likely to develop the disease. Pregnant women are prone to adopt a posterior upper body position due to the influence of the fetus, which causes uneven forces on the discs and a tendency for the vertebrae to be misaligned, which makes them more prone to lumbar disc herniation.