Welcome to the forum . .
First thing to do is backup any data you cherish . . then Suggest you start talking to the manufacturer support . . they will probably have you run a diagnostic to check the drive, which may be failing.
If you want to do it yourself, you can download a diagnostic from one of these:
Samsung
http://www.samsungelectronics.com/hd...ies_index.html
Seagate
http://www.seagate.com/support/seatools/index.html
Maxtor/Quantum
http://www.maxtor.com/en/support/products/index.htm
Western Digital
http://support.wdc.com/download/
IBM/Hitachi
http://www.hgst.com/hdd/support/download.htm#DFT
fujitsu/Seimens
http://www.fcpa.fujitsu.com/download...es/#diagnostic
IBM/Hitachi
http://www.hgst.com/hdd/support/download.htm#DFT