Pain is caused by (semi) solid matter on the wrong place in the body. From bones and muscles which are moving not quite correctly and therefore pressing on other tissue, food or bacteria in the digestive system who are causing havoc, to a wrong balance of minerals in the brain.
Seen through the spiritual structure, pain is caused by consciousness which goes to the wrong direction. Ways and manners of which we think we have to work accordingly, which cause wrong movements. Things we don’t want to do, but try to do nevertheless. Thoughts we do think, but blockade in our minds.