Back pain may be due to multiple reasons. A detailed evaluation is needed to determine the cause. If you have stiffness along with it or if pain is worse at night or early morning, or if it is associated with heel pain, then it may be due to Arthritis (Ankylosing Spondylitis).
Next Steps
If you have any of the above symptoms consult a Rheumatologist. If you don't have any of the above, consult an orthopedic surgeon.