Hi, I am 35 years old, female. I have had upper back pain since two weeks ago. It just started one morning from shoulders, then started radiating to lower for few days, now it has reached my tail bone. But I have sharp but very short pain in different parts of my back just jumping from one location to other. I had right and left rib x-ray (because at that time pain was in upper). I am going to see my family doctor. I am ANA positive with last titer 1:160 (15 months ago), Homegenous pattern. I was tested for Lupus as that time with negative results. Do you have any clue for now? Is this can be Ankylosing Spondylitis? is this a potentially life threatning?