Sleeping poorly directly causes a whole host of problems, ranging from muscular aches and pains, weight gain, through to an increased tendency for low mood and depresssion.
Sure, poor sleep can start because of some other problem (a painful spine, for example), and then itself feed back to aggravate the original problem or cause others, but whatever the cause of the sleep problem, it must be identified and addressed as a matter of urgency.
Sleep problems are tough to fix, but they can be - but rarely are they helped by the usual GP medications, so be careful of those.
Check out this survey / site which has a host of useful information …
http://www.howdidyousleep.org/