iMac Icon Not Opening From Desktop

So I have an iMac that's about 3 years old, and the last couple of months I started having trouble opening the hard drive from the iMac icon on the desktop. I click on it, and it blinks, the desktop page looks like it almost refreshes or something, and nothing happens. I usually have to click on it between 5-10 times before it opens, and it's getting worse lately. I have done no tinkering or repair for this issue aside from restarting the computer, so I'm not really sure how to approach this. Has anyone else had this issue, and if so, how did you fix it? Any advice you can offer would be appreciated.

Have a look here and after that if need be post back along with Mac model and current OS.