Your carry a heavy load.
Try spreading out the weight by wearing a cros-body bag or holding a purse over one shoulder and a tote over the other; so there's less strain on any one part of your back.
You're a desk jockey.
Sitting all day ''puts more pressure on your back than standing'' Dr.Khanna says. Buy a standing desk if you can,or use a lumbar-support pillow and get up every half hour.
Smokers are about a third more likely to have lower-back pain, per a 2010 Finnish review. Docs aren't sure exactly why, but smoking reduces blood supply to the spine .