58 year old female, fusion @L4-5 in 2002, w/terrific results. (No family history). Have been treated for lower back pain, right hip pain, numbness in thighs, for over a year, with facet injections, radio frequency, epidurals, and drugs. Recent MRI shows a severely herniated disk at L3-4, and I've been referred to an orthopaedic doctor for evaluation. My question is...If left untreated, what damage or effects can this herniation cause?