The RAM in your Mac is in essence the active workspace of your computer, in which your programs run and your content is created. Because of this, healthy RAM is vital for properly running any software on your Mac, be it the system software that comes with OS X or third-party programs.
Unfortunately, if the RAM in your Mac is faulty, those faults can sometimes persist undetected for a while, only to crop up unexpectedly and result in a crash, hang, or other unwanted behavior. Therefore, it is good to not only be able to identify faulty RAM, but also be able to properly test for it and then be prepared to fix the problem, if it arises.
Use EtreCheck to analyze your RAM memory:
You might not have enough Free RAM, like the example below:
Fortunately, Activity Monitor makes this easy for you - open /Application/Utilities/Activity Monitor.app and look at the Memory tab to see which applications are using the most memory. Decide if they need to be running.
For a deeper check, click Share Report and forward it to firstname.lastname@example.org so we can check the report ourselves!