I am suffering from backache in inferior region especially during the winter or if i carry a heavy things. so what's the possible problem with me ?

Back pain: Could be sprain or could be disc disease. Should seek help if getting worse.

Several options: Different conditions can cause backache, such as muscle weakness/deconditioning, lumbar sprain/strain, early disc degeneration, early arthritis in the spine joints, etc. The good news is, at your age the most likely diagnoses are not serious and will respond to basic conservative treatment including physical therapy and improved body mechanics.