See an orthopaedician
Thanks for your query.
Well looking into your problem I would like to tell you this there can be multiple causes but most common will be mechanical low back pain
in which there is disc degenerstive changes and due to compression of nerves there is radiating pain
Other thing can be spondyloarthropathy
which causes pain . Other rare causes can be discitis
, metastasis etc. I will advise you to see an orthopaedician for this as physical examination and certain tests like straight leg raising test will be required for this and making the diagnosis .
I do hope that you have found something helpful and I will be glad to answer any further query.