First, backup up your data. Then open Disk Utility in the Utilities folder. Click on your drive. Down at the bottom of the window you'll see a listing labeled 'S.M.A.R.T Status". If it says Verified then your drive may not be dying. If it says Failing then your drive is dying.
Important Note: S.M.A.R.T. can be wrong. It may say verified but the drive could still be failing. So backup you data.