I have pain in my back for long time ago, no body was able to give what is the problem? All test you imagine was done, they told me arthitis vry mild,

Age? If you are below 40, you need a CRP done. Most doctors order a b27 tests when looking for inflammatory disease, but this is an error, since many other "hla" types are associated with this. Core stengthening will help. But you experience pain at night or pain and stiffness in the morning, it is probably inflammation. If the reverse is true-mechanical, even though your x-rays are "negative.".