question: I have a severe needle like pain at the left side of my lower back. I visited a doctor recently and he suspects that there might be a cyst at the L4 L5 region. He has asked me to get an ultrasound done and an x-ray. What kind of a cyst can this be. I have been having this pain for about 4 years now. and never bothered. Only now as the pain increased, i thought i must visit a doctor. since then i am  extremely worried.