What Causes Sciatica?

Anything capable of physically compressing the sciatic nerve or the nerve roots that form it has the potential to cause sciatica.  Common causes are:

• Lumbar disc herniation pressing a nerve root
• Spinal stenosis (narrowing of the canals where nerve roots pass) from degenerative disc disease
• Piriformis syndrome:  pinching of the sciatic nerve by the piriformis muscle— one of the hip mover muscles
• Pelvic mass (tumor, cyst)
• Third trimester pregnancy
• Prolonged sitting; direct, continuous pressure on the sciatic nerve
• Brain tumor affecting the cell nuclei of sciatic nerve motor neurons in the brain

SPINAL STENOSIS – Note how the central canal has narrowed to the point it is contacting the nerve roots inside.

NEXT:  The Three, Main Presentations of Sciatica