Disks are the soft, rubbery pads found between the spine's vertebrae. When stressed or overused from wear-and-tear, the center of the disk can push through its outer edge, putting pressure on nearby sensitive nerves.

The American Academy of Orthopaedic Surgeons lists these common risk factors for herniated disks:

• Lifting objects the wrong way.
  
  
• Smoking.
  
  
• Being overweight, which causes stress on the spine.
  
  
• Applying sudden pressure, even slight, on the spine.
  
  
• Engaging in repetitive strenuous activities.