Depends on the cause of the pain. You should see a doctor to be correctly examined and they will advise the best treatment. Back pain can be a symptom of other illnesses so always best to get proper medical advice rather than asking online.
I think the best thing you can do for Back Pain is to go Bike Riding. It has the most magical natural self healing capabilities. I am not sure what is, but Biking does magic for Back pain. At least it does with me over anything else. But make sure the Temperature is Warm and not too cold which will make muscles to tense up.
Acupuncture can Help your Back pain.
The entire process of acupuncture is based on the theory that we have a life force that is commonly known as qi. This life force can be manipulated by interrupting or redirected through the insertion of tiny needles into specific areas of the body. Although medical science is unable to really identify how this process works, far too many people have been helped by it for it to be a coincidence. Some people theorize that acupuncture helps to release chemicals into the system that may act as painkillers, but it is really unknown why it works.
The amount of rest you get is important, and so is the position you get it in. “Sleeping in a bad position or on a mattress without support can cause back pain,” Wilmarth says.
Back sleepers should put pillows under their knees.
Side sleepers should place pillows between their knees to keep their spine in a neutral position. This is specially IMPORTANT.
Stomach sleeping causes the neck and head to twist and can put undue stress on the back.
And ya, Eat less as bumpercrop said, to reduce pressure on stomach walls.