MacBook – 2010 Macbook pro makes intermitten beeping sound

Number one, backup immediately. At least if it dies you got all your data. I would recommend using a drive scanning utility to check your drive for hardware issues. S.M.A.R.T is useless, its pretty good that telling you that your drive is already dead.

All the really good utils aren't free. Techtool Pro has been my tool of choice, however its not cheap.

While you're at it install Disk Drill to get temps for your drive make sure its not over heating and also get some recovery mechanism in place (other than time machine). The basic edition is free. You can grab it from here: http://www.cleverfiles.com/

I'd say this is almost certainly a hardware issue. Likely something internal to the drive (if it sounds like it spins up normally, probably some part of the onboard electronics), the hard drive cable or the SATA controller on the logic board.

I'd advise taking it in to an Apple store if you can (especially if it's under warranty), but if you want to try it yourself, the first thing to do is try a different drive, and see if that gets recognized. If it does, your drive is dead, if not, it's a problem with the logic board or the cable. You can get replacement parts from iFixit, but if it's the logic board, then you're better off getting a quote from Apple for a replacement.