What causes herniated discs?Herniated discs are caused by aging, degeneration of the disc (disc disease) or injury to the spine. A herniated disc can be caused by any type of intense pressure on the disk by the vertebrae above and below it. This could be caused by lifting a heavy object improperly, by sudden twisting, by a weakening of the disc covering that occurs with age, or by traumatic injury
to the back area. Obesity can also put pressure on the disks, and smoking can contribute to degeneration of the disc material. When the soft interior of the disc bulges out, it places pressure on the nearby nerves of the spinal cord. Disc disease may result from tiny tears or cracks in the outer shell (capsule) of the disc. The jelly-like material inside the disc (nucleus) may be forced out through the tears or cracks in the capsule. This causes the disc to bulge, break open or break into sections.
A herniated disc usually is caused by wear and tear of the disc (also called disc degeneration). As we age, our vertebral discs lose some of the fluid that helps them maintain flexibility. A herniated disc also may result from injuries to the spine, which may cause tiny tears or cracks in the outer layer (annulus or capsule) of the disc. The jellylike material inside the disc (nucleus) may be forced out through the tears or cracks in the capsule, which causes the disc to bulge, break open (rupture), or break into fragments. Herniated disks are rare in young people, but common among people aged 35 to 55. Of all the factors responsible for herniated discs, aging is probably the most important. With age, the disc's outer shell appears to degenerate slowly, possibly because of decades of upright posture and back flexion. In some families, several close relatives suffer from herniated disks, whereas other families are not affected at all. If the condition runs in a family, it may have an unusually early onset, even striking people younger than 21. Studies are beginning to identify specific genes linked to inherited forms of disc disease.