What are the possible ways to treat back pain in early pregnancy?

I am here for my wife. She is 26 years old and 3 weeks pregnant. Its going to be her first pregnancy and we are not sure about what all to expect. For the past one week she has been suffering from a disconcerting back pain which she wants to get rid of as quickly as possible. I would appreciate if people can suggest me the possible ways to treat back pain in early pregnancy!! Waiting for the replies!