Getting the gray question mark when I start my MacBook Pro

Hello,

I have been getting the gray question mark when I start my MacBook Pro (A1502 with 3.1GHz, i7). I've figured out how to navigate to the OS X utilities page. However, the HD isn't showing up and so there is nothing to try and fix the startup disk on/reinstall my OS on.

From what I've read, this is a HD problem. However, probably about every 20-30 attempts at starting up my laptop, it will start per normal and brings me to the normal login page, and everything runs fine from there.

Just wondering if I should do anything (aside from backing up files) while my Mac is currently up and running that can fix this issue, as i'm confident that once it shuts off, I'll have the same issues again. Also, if anyone has any thoughts on what the long-term prognosis is, those are welcome too.

Thanks!

[Re-Titled by Moderator]