Sciatica occurs when the sciatic nerve becomes pinched, usually by a herniated disk in your spine or by an overgrowth of bone (bone spur) on your vertebrae. More rarely, the nerve can be compressed by a tumor or damaged by a disease such as diabetes.

Risk factors

Risk factors for sciatica include:

• Age. Age-related changes in the spine, such as herniated disks and bone spurs, are the most common causes of sciatica.
• Obesity. By increasing the stress on your spine, excess body weight can contribute to the spinal changes that trigger sciatica.
• Occupation. A job that requires you to twist your back, carry heavy loads or drive a motor vehicle for long periods might play a role in sciatica, but there’s no conclusive evidence of this link.
• Prolonged sitting. People who sit for prolonged periods or have a sedentary lifestyle are more likely to develop sciatica than active people are.
• Diabetes. This condition, which affects the way your body uses blood sugar, increases your risk of nerve damage.