Bad posture, especially due to uncomfortable shoes, is the most common culprit.
If you are under 60 try this > Branched chain amino acid (BCAA) and take the recommended dose during a short period until the pain disappears.
haha....very vague question...need more details...but the most common reason for back pain is stress and lack of sleep....get some sleep n time for urself...meditation helps too
poor posture