Well, my wife believes that almost everything that happens to you emotionally -- stress, worry, happiness, sadness -- manifests itself in your body. They way your body runs is directly affected by how you feel about what is going on in your life. Sounds very reasonable to me. Supposedly, you find out what the worry or stress is and that back ache, shoulder ache, neck ache magically disappears. I've got a doozy of a back ache right now, that will likely last a week or more, but I hope I find out whatever problem that's going on in my life is so that it will hit the road. If you feel strongly about such things, say a little prayer for my aching back. It could use the help.
Cheers.